320 terms

Dictionary: S

S-1 registration statement: The filing a company must make before selling shares publicly, containing audited financials, risk factors, ownership, and the terms of the offering.
S&P Global PMI (flash): A separate family of purchasing manager surveys published for major economies, with a flash estimate released about a week before month-end covering roughly 85% of responses.
Safe haven currency: A currency that tends to attract flows during market stress, historically the US dollar, the Japanese yen and the Swiss franc, regardless of what caused the stress.
Safe withdrawal rate: The percentage of an initial portfolio that can be withdrawn annually, adjusted for inflation, with a high historical probability of lasting a given horizon.
Sahm rule: A recession indicator that triggers when the three-month average unemployment rate rises half a percentage point above its lowest three-month average of the prior year.
Same-store sales: Sales growth at locations open for at least a year, which separates genuine demand from the growth that simply comes from opening more stores.
Sample size: The number of trades behind a statistic; small samples make win rate and expectancy unreliable.
Sample size for an edge: The number of trades needed before a measured edge is distinguishable from luck, which is far larger than most traders assume.
Sanctions screening: Checking customers, counterparties and payments against government sanctions lists, blocking or rejecting prohibited transactions and reporting them to the relevant authority.
Sandbox environment: A broker-provided test environment that accepts orders without real money. Essential for testing plumbing and misleading about fills.
Sandwich attack: A bot buying just before your swap and selling just after it, pushing your fill to the worst price your slippage setting allows and pocketing the difference.
Santa Claus rally: The tendency for the last five trading days of December and the first two of January to show positive average returns.
Sarbanes-Oxley Act: The 2002 US law tightening corporate governance and financial reporting after Enron and WorldCom, requiring CEO and CFO certification and audits of internal control over financial reporting.
Scaling in: Building a position in planned tranches rather than all at once, to average the entry or wait for confirmation.
Scaling out: Closing part of a position at targets while letting the rest run, trading expectancy for a smoother equity curve.
Scaling plan: A prop-firm schedule that increases allowed contract size or account size as a funded trader hits profit milestones.
Scalping: A style that takes many small trades held for seconds to minutes, aiming to capture a few ticks each.
Scanning range: The price move a margin model assumes when stressing a portfolio — effectively the size of the one-day loss the exchange wants covered.
Scared money: Trading with capital you cannot afford to lose, which distorts every decision through the need for this trade to work.
Scenario analysis: Working through specific named situations - a rate shock, an earnings miss, a liquidity freeze - and pricing what each would do to the book.
Schedule 13D: The filing required when an investor crosses 5% of a class of shares with intent to influence the company; it must disclose the stake, the financing, and the purpose.
Schedule 13G: The short-form ownership filing for passive holders above 5%, used by index funds and long-only managers who have no intention of influencing control.
Schedule C for a trading business: The US form on which a trader with trader tax status reports business expenses; trading gains normally stay on Schedule D unless a 475(f) election moves them to ordinary income.
Schedule D: The US tax form summarising capital gains and losses, netting short and long-term results, applying the annual loss limit and tracking carryovers to future years.
Schedule K-1: The US tax form a partnership issues to each partner reporting their share of income, deductions and credits, used instead of the simpler forms issued by corporations and funds.
Screen hypnosis: The trance-like absorption that comes from staring at a moving chart, where time disappears and you start reacting to ticks rather than to your plan.
Seagull spread: A three-legged structure — typically long a call spread financed by a short put — used to get directional exposure for close to zero premium.
Seasonal adjustment: Statistical removal of predictable within-year patterns so that consecutive months can be compared; it can distort badly when the underlying seasonal pattern itself changes.
Seasonality (commodity): The recurring annual pattern in a commodity's supply, demand and price, driven by harvests, weather, heating and cooling cycles and driving seasons.
SEC (Securities and Exchange Commission): The US federal regulator for securities markets, including stocks, bonds, ETFs, and the exchanges and brokers that trade them.
SEC comment letter: A staff letter questioning a company's filings, and the company's response; both are published on EDGAR after the review closes.
Second-guessing: Re-litigating a decision that is already made, during the trade, which usually produces a worse exit than either the plan or patience.
Second-order Greeks: The sensitivities of the first-order Greeks themselves — gamma, vanna, charm, vomma and their relatives — which govern how a hedge decays.
Secondary offering: A sale of stock after the IPO. In the strict sense the seller is an existing holder; in common usage it also covers new shares sold by the company.
Section 1256 contracts: US tax treatment for regulated futures, broad-based index options, and certain forex contracts: 60% long-term and 40% short-term gains, marked to market at year end.
Section 16 insider: An officer, director or beneficial owner of more than 10% of a registered class of equity, subject to ownership reporting on Forms 3, 4 and 5 and to short-swing profit recovery.
Section 475(f) mark-to-market election: A US election letting a qualifying trader treat securities gains and losses as ordinary and mark open positions to market at year end, removing wash sales and the capital loss cap.
Section 988: The US rules taxing foreign currency gains and losses as ordinary income rather than capital, the default for spot forex trading, with an election out for certain contracts.
Sector ETF: An exchange-traded fund holding only the companies in one industry sector, used to express a view on an industry without picking a single stock.
Sector exposure: How much of your risk sits in one industry group, which is usually far more than the position list suggests.
Sector rotation: Money moving between industry groups as the economic cycle or interest-rate outlook shifts.
Securities Act of 1933: The US statute governing the offer and sale of new securities, requiring registration and a prospectus unless an exemption applies, and imposing liability for material misstatements.
Securities Exchange Act of 1934: The US statute governing secondary market trading; it created the SEC and covers broker registration, exchange regulation, periodic reporting, proxy rules and antifraud liability.
Securities information processor (SIP): The regulated utility that aggregates quotes and trades from every US equity venue into the consolidated tape and the published NBBO.
Securities Investor Protection Corporation (SIPC): A US non-profit funded by member brokers that returns missing cash and securities to customers when a brokerage fails; it does not cover market losses.
Securities lending: The business of lending shares to short sellers against collateral, in exchange for a fee; it is what makes short selling physically possible.
SEDOL: A seven-character identifier assigned by the London Stock Exchange, specific to a security on a particular exchange and in a particular currency.
Seed phrase: A list of 12 or 24 words that regenerates every private key in a wallet; the single most valuable secret a crypto user holds.
Segment reporting: The breakdown of revenue and profit by business line or region that companies must disclose, usually the most useful pages in the whole filing.
Segregated client funds: Client deposits held in bank accounts separate from the broker's own money, so they are not part of the firm's assets if it fails.
Selection bias: Drawing conclusions from a sample that was not chosen independently of the outcome you are measuring.
Self-attribution bias: Crediting wins to your skill and blaming losses on the market, news, or bad luck, which makes learning from results almost impossible.
Self-custody: Holding your own private keys rather than trusting a company; it removes counterparty risk and makes you fully responsible for security.
Self-efficacy: Your belief in your ability to execute a specific task, which predicts persistence through drawdowns better than general confidence does.
Self-employment tax on prop firm payouts: US prop firm payouts are usually paid to an independent contractor and reported on 1099-NEC, which makes them self-employment income subject to Social Security and Medicare tax.
Self-exclusion: Deliberately removing your own access - closing accounts, blocking platforms, handing over control - so that stopping does not depend on willpower each day.
Self-fulfilling prophecy: The argument that some technical levels work only because enough traders watch them and place real orders there.
Self-match prevention: An exchange control that cancels one or both orders when a firm's own buy and sell orders would trade against each other, preventing accidental wash trades.
Self-regulatory organization (SRO): A private body that writes and enforces rules for its own members under government oversight, such as FINRA in the US or the NFA for futures.
Self-talk: The running internal commentary during a session, which shapes behaviour and can be redirected toward instructions rather than judgements.
Self-trade prevention: Venue functionality that stops orders from the same firm or account matching each other, since trading with yourself creates volume without transferring risk.
Sell in May: The observation that equity returns have historically been weaker from May to October than from November to April.
Sell the rip: Selling into a sharp rally, on the view that the strength is temporary - the mirror of buy the dip.
Sending it: Executing a trade decisively and without hesitation, often with the implication that little analysis was involved.
Seniority: A claim's rank in the queue for repayment if the borrower fails; secured lenders are paid before senior unsecured bondholders, who are paid before subordinated holders and equity.
Senkou span: The two Ichimoku lines plotted twenty-six periods into the future, whose area between them forms the cloud.
Sensitivity analysis: Recomputing a valuation across a grid of key assumptions, usually discount rate and terminal growth, to show the range rather than a single number.
Separately managed account: A portfolio run by a manager in the investor's own name and custody account, rather than pooled with other investors' money in a fund.
Sequence of returns risk: The risk that the order in which returns arrive ruins a plan, even when the average return is fine; it bites hardest when money is being withdrawn.
Sequence risk: The fact that the same set of trades in a different order produces a different ending balance once size compounds.
Sequencer: The operator that orders transactions on a layer 2; usually a single entity, which is most L2s' biggest live trust assumption.
Sequential growth: One quarter compared with the immediately preceding quarter; the fastest read on a turning point, but heavily distorted by seasonality.
Serial correlation of returns: Whether periods of profit and loss cluster rather than arriving independently, which changes drawdown estimates and every ratio built on volatility.
Series 3: The US qualification exam for individuals soliciting futures or options-on-futures business, required for most associated persons, CTAs and CPOs.
Series 63: A short state law exam required in most US states before a registered representative may transact business with residents of that state.
Series 65: The exam most US states require of an investment adviser representative who is not already carrying a Series 7 plus Series 66 combination.
Series 66: A combined state exam covering both agent and adviser representative law, available only to candidates who also hold the Series 7.
Series 7: The main US qualification exam for a registered representative selling a broad range of securities, taken with the Securities Industry Essentials exam and firm sponsorship.
Session breaks: Vertical markers separating the regular trading session from overnight or global sessions on a 24-hour chart.
Session calendar: The record of which days and hours each market was open, including holidays, half days, and historical schedule changes.
Session VWAP: Volume weighted average price calculated from the start of the current trading session, resetting each day.
Settlement: The official daily closing price used to mark futures accounts, and the process by which a contract is closed out at expiry.
Settlement cycle: The number of business days between trade date and the date cash and securities actually change hands, written as T plus a number.
Settlement price: The official closing price an exchange calculates for each contract month, used for marking positions and setting margin.
Setup: A specific, repeatable set of conditions that must be present before you consider a trade, defined precisely enough for someone else to identify it.
SG&A: Selling, general and administrative expense: sales commissions, marketing, executive pay, finance, legal, HR and offices.
Shakeout: A sharp adverse move that removes weakly committed holders before the original direction resumes.
Shame spiral: A loss taken as evidence about your worth, producing secrecy and avoidance, which prevents the review that would break the cycle.
Share buyback: A company buying its own shares in the market, reducing share count and lifting earnings per share if earnings hold steady.
Share CFD: A CFD tracking one company's share price, usually priced on the underlying exchange quote with commission charged per side, and carrying the lowest leverage of the CFD classes.
Share class: A variant of the same fund with different fee terms, currency treatment, income handling or minimum investment, all backed by one shared portfolio.
Share class: A separate series of a company's stock with its own rights, ticker, and often its own price, such as Class A versus Class B.
Share count trend: The direction of diluted shares outstanding over several years, which decides whether buybacks are genuinely returning capital or merely offsetting issuance.
Share recall: The lender's right to demand borrowed shares back at any time, which can force a short seller to cover regardless of how the trade is going.
Share sizing formula: Position size equals dollar risk divided by stop distance, adjusted for contract multipliers.
Shareholder yield: Dividends plus net buybacks plus net debt reduction, divided by market cap: total cash returned to shareholders.
Shareholders equity: What is left of assets after every liability is settled, made up of paid-in capital, retained earnings and accumulated other comprehensive income.
Shares outstanding: The shares currently held by all investors, including insiders; the denominator for market cap and earnings per share.
Sharpe inflation: The upward bias in a reported Sharpe ratio caused by testing many strategies and reporting the best, or by using returns that hide their own risk.
Sharpe ratio: Return above the risk-free rate divided by the volatility of those returns; a measure of reward per unit of risk.
Shelf registration: A pre-cleared registration letting a company sell securities in stages over up to three years, so an offering can be launched in hours rather than weeks.
Shell company: A listed company with no meaningful operations, kept alive for its listing, which can be used for a reverse merger or abused in promotions.
Shill: To promote a position or project to benefit your own holdings, or the person doing it.
Shooting star: A candle after an advance with a small body near the low and a long upper shadow, showing a failed push higher.
Short butterfly: The inverted butterfly: short the wings, long two at the body. A small credit that pays if the underlying finishes outside the wings.
Short exempt order: A short sale marked as exempt from the price test that applies when a stock has triggered the short-sale circuit breaker.
Short hedge: Selling futures to protect against a fall in the price of something you own or will produce.
Short interest: The number of shares sold short and not yet covered, usually expressed as a percentage of float.
Short premium: Any position that is net short extrinsic value, so time decay helps and rising implied volatility hurts.
Short rebate: The interest a short seller receives on the cash proceeds posted as collateral for borrowed shares, net of the lending fee. A negative rebate means the seller pays.
Short sale circuit breaker: A restriction armed when a stock falls 10% from the prior close, permitting short sales only at prices above the current national best bid for the rest of that day and the next.
Short selling: Selling borrowed shares in the hope of buying them back later at a lower price.
Short selling via CFD: Taking a bearish position by selling a CFD, which requires no stock borrow by the client and no uptick rule, but still carries borrow costs, dividend debits and regulatory bans.
Short squeeze: A rapid rally driven by short sellers being forced to buy back shares, which pushes price higher and forces more covering.
Short volatility trade: Any position that profits from calm and decay — selling options, shorting volatility futures, or holding inverse volatility products.
Short-dated options: Contracts with days rather than months to expiry, where gamma dominates, theta is large, and vega is almost irrelevant.
Short-swing profit rule: A strict-liability US rule requiring insiders to disgorge profits from any purchase and sale, in either order, within six months of each other, regardless of intent or information.
Short-term capital gain: A gain on an asset held one year or less, taxed in the United States at ordinary income rates, which is how almost all active trading profit is treated.
Short-term debt: Borrowings due within twelve months, including commercial paper, revolving credit drawings and the slice of long-term loans maturing next year.
Side pocket: A segregated sub-account holding illiquid or hard-to-value positions, which existing investors keep a claim on while the main fund continues to deal normally.
Sidechain: A separate blockchain with its own consensus and security, connected to a main chain only by a bridge.
Signal: A computed condition or number that tells a system to act: enter, exit, or change position size.
Signal group: A paid or free chat where someone posts entries and exits for others to copy - which transfers the decisions without transferring any skill.
Signal lag: The deliberate delay between the data a signal uses and the moment the resulting order can execute. Getting it wrong is the most common way to fake a backtest.
Signal line: A moving average of an indicator plotted on top of it, so that crossings between the two generate mechanical buy and sell triggers.
Signal-to-noise ratio: How large a real effect is relative to the random variation around it; in financial returns it is usually tiny.
Significance level: The p-value threshold you commit to before testing, conventionally 0.05, below which you are willing to reject the null hypothesis.
Silver futures (SI): COMEX contracts on 5,000 troy ounces of refined silver, quoted in cents per ounce with a half-cent tick worth $25.
Sim-funded account: A prop firm account that pays real money on profits but places no orders in the market, so performance is measured against a simulated fill engine rather than live executions.
Simple moving average: The plain average of the last N closing prices, recalculated each bar, giving every bar in the window equal weight.
Simple returns: The plain percentage change, (P1 - P0)/P0. What your account statement shows, and the right choice when adding returns across positions in the same period.
Single prints: Prices in a market profile touched during only one time bracket, marking areas the market moved through quickly without accepting.
Single-dealer platform: An electronic venue run by one bank or trading firm where clients trade against that firm's prices only, not against each other.
Single-name limit: A hard cap on how much risk or capital any one instrument may take, independent of how good the idea looks.
Sinking fund: A provision requiring the issuer to retire part of an issue each year, either by open-market purchase or by redeeming bonds selected at random at par.
SIPC coverage limits: SIPC protects up to $500,000 per customer per capacity, of which at most $250,000 may be cash, and only against a failed broker, never against losses.
SIPC protection: US coverage that restores missing customer securities and cash if a broker fails, up to $500,000 per customer with a $250,000 sub-limit on cash.
SIPP: United Kingdom: a personal pension giving tax relief on contributions and tax-free growth inside the wrapper, with access restricted until a minimum pension age.
Size factor: The historical tendency for smaller companies to outperform larger ones, and the risk and liquidity characteristics that come with owning them.
Size up: To increase position size - legitimate when it follows a rule, and one of the most common places a plan quietly dies when it does not.
Sizing drift: The slow, unplanned growth of position size that happens when sizing rules are not recalculated.
Sizing on closed equity: Basing position size on realised account value, ignoring unrealised profit in open trades.
Sizing on open equity: Basing position size on account value including unrealised profit and loss, which compounds faster in both directions.
Skew index: A published measure of how steeply out-of-the-money index puts are priced relative to at-the-money options; a gauge of perceived tail risk.
Skewness: A measure of asymmetry in a return distribution. Negative skew means many small gains and occasional large losses; positive skew is the reverse.
Slashing: A protocol penalty that destroys part of a validator's staked coins for provably harmful behaviour such as double-signing.
Sleep debt: Accumulated short sleep, which degrades impulse control, risk judgement, and self-assessment - while leaving you feeling roughly normal.
Slippage: The difference between the price you expected and the price you actually got filled at.
Slippage budget: An explicit allowance for execution costs built into your risk and expectancy numbers, rather than a surprise discovered afterwards.
Slippage measurement: The discipline of quantifying the difference between an intended price and the achieved price, using a benchmark fixed in advance rather than chosen afterwards.
Slippage model: The rule your backtest uses to convert a theoretical price into a realistic one. It can be a fixed number of ticks, a fraction of the spread, or a function of size and volatility.
Slippage tolerance: The maximum adverse price move you authorise between submitting a swap and its execution. Set too low the trade reverts; too high and it invites sandwiching.
Slow stochastic: A smoothed version of the stochastic oscillator that averages the raw %K before plotting, reducing false crosses at the cost of extra lag.
Small-cap: Companies worth roughly $300 million to $2 billion; higher volatility, thinner liquidity, wider spreads, and frequent share issuance.
Smart beta: Rules-based index products that deliberately deviate from cap weighting to capture a factor tilt, priced between plain index funds and active management.
Smart contract wallet: A wallet that is itself a programmable contract, allowing recovery, spending limits and sponsored gas instead of a single fixed key.
Smart money: Institutional or professional participants assumed to be better informed - a useful label that is often used far beyond what anyone can actually observe.
Smart order router (SOR): Software that splits and sequences an order across venues automatically, chasing the best available price, size and fee outcome.
Smart order routing: Software that decides which venue each slice of an order goes to, based on displayed liquidity, fees, fill probability and latency.
Sniper algorithm: An opportunistic algorithm that stays hidden and fires only when it detects liquidity at or better than a limit you set.
Social proof: Treating other people's behaviour as evidence about what is correct, which in markets means a loud consensus feels like research.
SOFR (Secured Overnight Financing Rate): The volume-weighted median rate on overnight Treasury repo, published daily by the New York Fed and the main US dollar benchmark rate.
SOFR futures: Cash-settled contracts on the Secured Overnight Financing Rate, the successor to Eurodollar futures and the main instrument for trading short-term US rate expectations.
Soft dollars: An arrangement where a manager directs trades to a broker at higher commission rates in exchange for research or services, paid indirectly out of client trading costs.
Soft fork: A protocol change that only tightens the rules, so non-upgraded nodes still accept the new blocks.
Soft landing and hard landing: A soft landing is inflation returning to target without a recession; a hard landing is the same disinflation achieved through a contraction and rising unemployment.
Soft rug: A project that abandons users gradually rather than stealing outright: the team sells, development stops, and the token bleeds to nothing.
SOPR: The ratio of price at which coins are sold to the price at which they were acquired, aggregated across all coins moved that day.
Sortino ratio: Like the Sharpe ratio but dividing by downside deviation only, on the argument that upside volatility is not a risk anyone wants reduced.
Source of funds and source of wealth: The origin of the specific money being deposited and, separately, of the customer's overall wealth; both must be understood and evidenced for higher-risk relationships.
Soybean futures (ZS): CBOT contracts on 5,000 bushels of number 2 yellow soybeans, the anchor of the crush complex and the most China-sensitive US agricultural market.
Soybean meal futures (ZM): CBOT contracts on 100 short tons of soybean meal, the protein feed that is the larger share of the crushing margin by value.
Soybean oil futures (ZL): CBOT contracts on 60,000 pounds of crude soybean oil, quoted in cents per pound, increasingly driven by renewable diesel policy rather than food demand.
SPAC redemption: The right of a SPAC shareholder to hand shares back for their share of the trust, plus interest, rather than participate in the announced merger.
SPAN 2: CME's newer margin framework, which replaces SPAN's fixed scenario grid with a value-at-risk model plus explicit add-ons for liquidity and concentration.
SPAN margin: The CME's portfolio margining system, which sets requirements by simulating a portfolio's worst plausible one-day loss across price and volatility scenarios.
Spark spread: The margin a gas-fired power plant earns: the price of electricity minus the cost of the natural gas needed to generate it.
Special (repo): A security so in demand as collateral that its owners can borrow cash against it below the general collateral rate.
Special dividend: A one-off payment outside the regular schedule, usually after an asset sale or an unusually strong year; it is not expected to repeat.
Special opening quotation (SOQ): A settlement value built from the opening prints of every index constituent, used to expire index futures and options.
Special purpose acquisition company: A listed shell with no operations that raises cash in an IPO and then hunts for a private company to merge with, taking it public in the process.
Specific identification: Choosing exactly which tax lots are sold, instructed to the broker at or before settlement, to control the size and holding period of the reported gain. United States.
Speculative stock: A stock with no established earnings whose value depends on a future outcome, such as a clinical trial, a drilling result, or a single contract.
Speculator: A participant who takes futures risk deliberately in pursuit of profit, with no underlying physical exposure to offset.
Speed: The third-order Greek measuring how gamma changes as the underlying moves; it describes how quickly a hedge goes stale.
Spin-off: A parent company distributes shares of a subsidiary to its own shareholders, creating a separate listed company at no cost to holders.
Spinning top: A candle with a small body and long shadows on both sides, showing a period of conflict that ended roughly where it started.
Split-off: A parent offers its shareholders the chance to exchange parent shares for shares of a subsidiary, shrinking the parent's share count.
Sponsored access: A client trading under a broker's market participant identifier with its own connection to the venue, permitted only with the broker's pre-trade risk controls in the path.
Spoofing: Placing large orders with the intent to cancel them before execution, to trick others about supply or demand; illegal in the US since 2010.
Spot date: The day a spot FX trade actually settles, normally two business days after the trade date, with a few pairs settling next day.
Spot FX: A currency trade for near-immediate delivery, normally settling two business days after the deal, and the reference point for every other FX instrument.
Spot month: The contract month currently in its delivery period, where physical settlement rules and tighter position limits apply.
Spot rate: The yield on a single cash flow received at one future date, with no intermediate coupons; the true building block of bond pricing.
Spread (statistical): The combination of two or more instruments that a relative-value trader actually holds, constructed so the combined series mean-reverts.
Spread betting: A UK and Ireland product where a trader stakes an amount per point of movement in a market, structured legally as a bet rather than as a purchase of any instrument.
Spread betting tax treatment (UK): In the UK, spread betting profits are generally treated as gambling winnings and fall outside capital gains tax and stamp duty, while CFD profits are generally within the capital gains regime.
Spread duration: How much a credit bond's price moves for a one percentage point change in its credit spread, holding Treasury yields constant.
Spread margin credit: The reduction in margin an exchange grants for positions that offset each other, such as two months of the same product.
Spread order (combination order): One order for two or more legs executed as a unit at a net price, so you are never left holding half a strategy.
Spread widening: The temporary or scheduled increase in the gap between bid and ask when liquidity thins, typically at rollover, around data, and over weekends.
Spread width: The distance between the strikes in a vertical spread; it sets the maximum value of the spread and therefore the risk.
Spring: A brief dip below the floor of an accumulation range that fails to attract follow-through selling and quickly reverses back inside.
SPX-style index options: Large-notional, cash-settled, European-style options on a broad equity index; the institutional standard for index hedging.
Squeezed: Being forced out of a position by an adverse move, particularly a short forced to cover into rising prices.
Stablecoin: A crypto token designed to hold a fixed value, usually one US dollar, backed by reserves or by algorithms.
Stableswap pool: An AMM curve tuned for assets that should trade near parity, offering very low price impact near the peg and steep pricing once it breaks.
Stagflation: The combination of weak growth, rising unemployment and high inflation, which forces a central bank with a dual mandate to choose which half to fail at.
Staking: Locking crypto to help secure a proof-of-stake network in exchange for periodic rewards, with lockup and slashing risks.
Stale price: An oracle value that has not updated recently enough to be trusted, leaving contracts acting on a price the market has already left behind.
Stamp duty reserve tax: United Kingdom: a transaction tax charged on purchases of UK incorporated shares, collected automatically on electronic settlement and added to the cost of the position.
Standard (monthly) expiration: The third-Friday contract that has been listed on US options since the beginning; usually the deepest and tightest line on the chain.
Standard deviation move: A move scaled in units of implied volatility; one standard deviation contains about 68% of outcomes under the model's assumptions, two about 95%.
Standard error: How much a sample statistic would wobble if you drew a different sample. For a mean it is the standard deviation divided by the square root of the count.
Standard error of expectancy: The uncertainty around your measured edge, computed from the spread of trade results and the number of trades.
Standard, mini, and micro lots: Forex position sizes: a standard lot is 100,000 units of the base currency, a mini lot 10,000, and a micro lot 1,000.
Standing repo facility (SRF): A Fed facility where eligible counterparties can borrow cash against Treasuries at a fixed rate, capping how high repo rates can go.
State channel: A private two-party ledger that settles on-chain only when opened and closed, allowing unlimited instant updates in between.
Static drawdown: A prop-firm loss limit fixed at a set level below the starting balance that does not move as you profit.
Stationarity: A series whose statistical properties do not drift over time. Prices are not stationary; returns and spreads usually are, which is why models are built on those.
Statistic stability: Whether a performance measure holds up across sub-periods, which separates a durable edge from one that worked in a single regime.
Statistical arbitrage: Systematic trading of many small positions selected by a statistical model, relying on the average across hundreds of bets rather than on confidence in any one.
Statistical power: The chance a test detects an effect that is genuinely there. Low power means your research mostly produces silence and flukes.
Status quo bias: Preferring things to stay as they are, so you leave positions, platforms, and habits untouched simply because changing requires a decision.
Steepener: A trade that profits when the gap between long and short yields widens, typically long the short maturity and short the long one.
Sterilised intervention: Currency intervention whose effect on the domestic money supply is deliberately offset by an opposite open market operation, so policy rates are left undisturbed.
Sterling flash crash (2016): The sudden collapse in GBP/USD during the early Asian session of 7 October 2016, which took the pair several percent lower within about two minutes before most of it was recovered.
Sterling ratio: Return divided by an average of the worst drawdowns rather than the single deepest one, which makes it more stable across samples.
Sticky delta: A surface regime where implied volatility attaches to moneyness rather than to a strike, so the whole skew shifts sideways as the underlying moves.
Sticky strike: A surface regime where each strike keeps its own implied volatility as the underlying moves, so at-the-money volatility changes with price.
Stochastic oscillator: An indicator showing where the close sits within the high-low range of the lookback period, on a scale from 0 to 100.
Stochastic RSI: The stochastic formula applied to RSI values instead of price, producing a much more sensitive oscillator that reaches extremes frequently.
Stock dividend: A dividend paid in additional shares rather than cash, which increases share count without changing the value of your holding.
Stock loan fee: The annualised rate a short seller pays to borrow shares, set by supply and demand for the specific security and charged daily on the position's market value.
Stock repair strategy: A ratio call spread added to a losing stock position that doubles the recovery rate up to a target price, paid for by capping gains there.
Stock replacement: Selling shares and buying deep in-the-money long-dated calls in their place, keeping most of the upside while freeing capital and capping downside.
Stock split: A company divides each share into more shares, cutting the price per share proportionally and leaving the value of your holding unchanged.
Stock-based compensation: Pay delivered in shares rather than cash; a real expense on the income statement and a steady source of share count growth.
Stock-based compensation as a percent of revenue: Share-based pay divided by revenue; a measure of how much of the workforce bill is being settled in equity rather than cash, and of the dilution that follows.
Stocks and shares ISA: United Kingdom: a tax-wrapped account in which investment growth, dividends and gains are free of UK income and capital gains tax, subject to an annual subscription limit.
Stonks: Deliberately misspelled stocks, used ironically to describe equity speculation that is not being taken seriously.
Stop distance: The gap between your entry price and your stop price, expressed per share, contract or pip.
Stop hunt: A move that pushes just past an obvious level where many stops sit, triggers them, and then reverses.
Stop level (minimum distance): The minimum distance from current price at which a broker will accept a pending order, stop loss or take profit.
Stop order: An order that becomes a market order once price trades through a trigger level.
Stop order slippage: The gap between a stop's trigger price and its actual fill, caused by the fact that a triggered stop becomes a market order into whatever liquidity remains.
Stop placement: Choosing the price level that proves the idea wrong, before choosing the size that makes the loss affordable.
Stop slippage: The gap between your stop price and the price you actually get, which is always against you on a triggered stop.
Stop-limit order: A stop order that becomes a limit order, not a market order, when triggered; safer on price, riskier on getting filled.
Stop-loss: A predefined exit that closes a losing trade at a set level, limiting how much one trade can cost you.
Stop-out level: The margin level at which a broker automatically starts closing your open positions, commonly 50% but set by the firm and by the rules of its regulator.
Stopping delivery: Being assigned the physical commodity as the holder of a long futures position, and paying the invoice in full to take title.
Storage cost: What it costs to hold a physical commodity for a period, and one of the main inputs to the shape of a futures curve.
STP broker: A broker that passes client orders automatically to external liquidity providers without manual intervention, usually earning a markup on the spread.
Straddle: Buying (or selling) a call and a put at the same strike and expiration; a bet on the size of a move rather than its direction.
Straddle rules: US tax rules for offsetting positions that defer losses on one leg while gains on the other are unrealised, suspend holding periods and capitalise certain carrying costs.
Strangle: Buying (or selling) an out-of-the-money call and an out-of-the-money put with the same expiration; cheaper than a straddle but needs a bigger move.
Strategic asset allocation: The long-term target weights a portfolio is built around, chosen from horizon and risk tolerance rather than from a view on the next quarter.
Strategy capacity: The largest amount of money a strategy can run before its own market impact and liquidity constraints erode the edge to nothing.
Strategy hopping: Abandoning a method during its normal losing stretch and adopting a new one, repeatedly, so no approach accumulates enough trades to be judged.
Strategy monitoring: The ongoing measurement of a live strategy against its expected behaviour, with thresholds decided before deployment for when to reduce size or stop.
Streak probability: The chance of a given run of wins or losses, which is computable in advance and almost always more likely than it feels.
Street name: Registration of shares in the broker's name rather than yours, with the broker recording you as the beneficial owner; this is how almost all retail stock is held.
Street name registration: Holding securities in the broker's nominee name at the depository rather than the investor's own name, which is how almost all modern brokerage positions are held.
Stress response: The physical cascade - adrenaline, then cortisol - that prepares you for threat and degrades exactly the abilities trading needs.
Stress test: Re-running a strategy under deliberately hostile assumptions to find what breaks it before the market does.
Stress testing: Revaluing a portfolio under deliberately severe conditions to find out what breaks, rather than estimating what is statistically likely.
Strike pinning: The tendency of a heavily traded underlying to close near a large-open-interest strike on expiration day, driven by hedging rather than opinion.
Strike price: The fixed price at which an option holder can buy (call) or sell (put) the underlying.
Strip: A simultaneous position in a consecutive run of contract months, traded as one package to lock in an average price or an average rate over a period.
Strip and strap: Weighted straddles: a strip is one call and two puts, a strap is two calls and one put, for volatility views with a directional lean.
STRIPS: US Treasury coupons and principal split into individually tradable zero-coupon pieces, each maturing on a single date.
Strong hands: Holders who can sit through volatility without selling, usually because of size, time horizon, and a thesis they can restate.
Structured product: A pre-packaged investment combining a debt instrument with one or more derivatives to produce a defined payoff linked to an index, basket, rate or single stock.
Style drift: A fund gradually taking on exposures outside its stated mandate, so that its risk profile no longer matches what investors selected.
Sub-penny rule: The Reg NMS rule barring displayed quotes in increments finer than one cent for stocks priced at or above one dollar, with a finer increment allowed below.
Subordinated debt: Debt that ranks behind senior claims in a default, paying a wider spread in exchange for taking losses first once secured and senior lenders are paid.
Substantially identical securities: The test deciding whether a replacement purchase triggers the wash sale rule; identical CUSIPs clearly count, and options and convertibles on the same underlying can too. United States.
Sugar futures (SB): ICE contracts on 112,000 pounds of raw cane sugar for export, quoted in cents per pound with a 0.01-cent tick worth $11.20.
Suitability: The older brokerage standard that a recommendation must fit the customer's profile, with reasonable-basis, customer-specific and quantitative components; largely superseded for retail by Reg BI.
Sum of the parts: Valuing each business segment separately at its own appropriate multiple, then adding them and subtracting net debt and central costs.
Summary of Economic Projections (SEP): The FOMC's quarterly published forecasts for growth, unemployment, inflation and the policy rate, released in March, June, September and December.
Sunk cost fallacy: Continuing to hold a losing position because of what it has already cost, rather than what it is worth now.
Super contango: A contango so steep that deferred futures exceed the nearby by more than the cost of storage, which happens only when physical storage has run out.
Super-voting shares: Shares carrying more than one vote each, used to keep control with insiders; often they convert to ordinary shares on sale or after a sunset date.
Superficial loss rule: Canada: a loss is denied when identical property is reacquired within 30 days before or after the sale and still held at the end of that period, with the loss added to cost base.
SuperTrend: A trailing line plotted a multiple of ATR from price, flipping sides when price closes through it, used as a simple always-in trend signal.
Supervised learning: Fitting a model to labelled examples so it can predict the label for new inputs. Nearly all practical machine learning in trading is of this kind.
Supply in profit: The share of all coins whose last on-chain movement was at a price below the current one, so the holder is nominally in the black.
Supply zone: A price area from which a sharp decline previously began, marked as a band rather than a line and watched for renewed selling.
Support: A price area where buying has previously stopped a decline and may do so again.
Survivorship bias: Drawing conclusions from the examples that survived while ignoring the ones that failed and disappeared.
Survivorship bias in trading advice: Learning from the small minority of traders and strategies that survived, while the identical approaches that failed are invisible.
Suspicious activity report (SAR): A confidential report filed with FinCEN when a firm knows or suspects a transaction involves illicit funds, evades reporting rules, or lacks any apparent lawful purpose.
Swap: A bilateral contract to exchange two streams of payments over time, defined by a notional amount that is usually never exchanged and used to convert one exposure into another.
Swap (rollover interest): The interest credited or charged for holding a forex position overnight, based on the rate difference between the two currencies.
Swap dealer: A COT category for banks and dealers that use futures to hedge over-the-counter swap exposure, typically the other side of commodity index products.
Swap route: The path a trade takes between pools to get from one token to another, for example A to ETH to USDC rather than a direct A-to-USDC pool.
Swap spread: The fixed swap rate minus the Treasury yield of the same maturity, a gauge of balance sheet costs, hedging demand and Treasury supply.
Swap-free account: An account type that does not charge or pay overnight interest, offered to comply with religious prohibitions on riba, usually with an administration fee instead.
Swaption: An option to enter an interest rate swap on set terms at a future date, giving the buyer the right to pay or receive fixed without the obligation to do so.
Sweep order: An order split across multiple exchanges simultaneously to take all available liquidity at once; read as a sign of urgency rather than patience.
Sweep-to-fill order: An order that is chopped into pieces and sent to several price levels or venues at once to capture size immediately.
Swing high: A bar whose high is higher than the highs of a set number of bars on either side, marking a local peak in price.
Swing low: A bar whose low is lower than the lows of a set number of bars on either side, marking a local trough in price.
Swing trading: Holding positions for days to weeks to capture a single move within a larger trend.
Swiss franc unpeg (2015): The removal of the Swiss National Bank's floor under EUR/CHF on 15 January 2015, which moved the pair by double digits in minutes and bankrupted several retail brokers.
Swissy: The Swiss franc, and the pair USD/CHF; the classic European safe haven currency.
Sybil attack: Creating many fake identities or wallets to gain a disproportionate share of rewards, votes or influence in a permissionless system.
Symmetrical triangle: A coil where highs fall and lows rise at roughly equal rates, contracting toward an apex with no directional bias of its own.
Syndicate stabilization: Permitted buying by the underwriter after an offering to keep the price from falling below the offer level, funded by the short position created by the greenshoe.
Synthetic call: Long stock plus a long put, which produces the same curved payoff as owning a call at that strike.
Synthetic data: Artificially generated price series used to test a strategy on markets that never happened, including deliberately hostile ones.
Synthetic long stock: Long a call and short a put at the same strike and expiration; a position with the payoff of 100 shares, built from options.
Synthetic put: Short stock plus a long call, producing the same payoff shape as owning a put at that strike.
Synthetic replication: Delivering an index return through a total return swap with a bank rather than by holding the constituents, which tightens tracking but introduces counterparty exposure.
Synthetic short stock: Short a call and long a put at the same strike and expiration; the payoff of 100 short shares without borrowing stock.
Synthetic straddle: A straddle-like payoff built from stock plus options rather than two options: for example 100 short shares against two long calls.
Systematic risk: The part of an asset's risk that comes from the market as a whole, which cannot be removed by holding more names.
Systematic trading: Trading where every decision comes from a written rule rather than a judgement call made in the moment.

Missing a term? Tell us and we will write it.