Binary events: FDA decisions and product launches

Earnings are the scheduled catalyst everyone shares. Beyond them sits a set of company-specific events that can move a stock more in a day than earnings do in a year. Some are truly binary, with two outcomes and almost nothing in between. This lesson covers the two most common, and the trading logic that applies to both.

What "binary" means for risk

A binary event has a small number of discrete outcomes, and the stock will gap to one of them. There is no "a little bit approved". For a trader this changes everything about the position:

• A stop cannot work. The stock does not pass through your stop level; it jumps over it.
• The options market prices the event explicitly, and the implied move is often 30% to 70% for small biotechs.
• The expected value of holding through depends entirely on your estimate of the probability of each outcome versus the market's. If you do not have a real edge in that estimate, the position is a coin flip with a skewed payout.

The risk management course says to size from the stop. When there is no stop, you size from the worst case: the position must be small enough that the worst outcome is a loss you planned for.

FDA decisions

For a drug developer, the regulatory calendar is the whole story. The main dated events:

Some vocabulary. A PDUFA date is the target date set under US law by which the FDA aims to act on a new drug application; it is public and usually announced by the company. A Complete Response Letter is a rejection that lists the deficiencies; it can be a small fix (months) or a fatal one (years). A trial "readout" is the release of top-line results, and it is often the biggest move of all, because approval is largely a formality once a trial clearly succeeds.

Historically, drugs that reach a PDUFA date after successful pivotal trials are approved more often than not, and the market knows it, so the asymmetry is usually: modest gain on approval, severe loss on rejection. For a small company whose only asset is the drug, rejection can mean −70% or worse. Larger companies with many products see much smaller moves.

ACME's binary event

Imagine ACME's subsidiary, ACME Bio, is a $600M market cap company with $150M of cash, one drug awaiting a PDUFA decision in 30 days, and no revenue. Options imply a move of ±55%.

A trader considering a long position writes down the outcomes:

A positive expected value on the trader's estimates. But two things must be true for the trade to make sense: the 70% must be an honest, informed estimate rather than a hope, and the position must be sized so that a −65% outcome is an acceptable loss. With 1R of $300 and a worst case of −65%, the maximum position is $300 ÷ 0.65 = $462. That is tiny compared with a normal swing position, and it is correct: the trade's downside is 65% of whatever is invested, and the only lever is size.

Key idea: On a binary event there is no stop, so position size comes from the worst-case outcome, not from a chart level. If the worst case is −65%, the position is 1R ÷ 0.65.

Most traders without domain knowledge are better off not holding through drug decisions at all, and instead trading the aftermath: the days after an approval, when a company's story changes from "will it" to "how much will it sell", often produce more orderly trends with real stops.

Product launches

For hardware, software, consumer and automotive companies, the launch of a major product is a softer version of the same thing. It is rarely binary (a product can be a modest success), but it has a known date, an expectations game, and an information sequence a trader can follow.

The sequence:

1. Announcement. The product is revealed. The stock often runs into it and sells the news, exactly as with earnings.
2. Pre-order and early demand data. Third-party surveys, app-store rankings, dealer checks, web traffic. Often noisy, often moves the stock.
3. Launch and first reviews. A well-reviewed product that ships on time is usually already priced; a delay or a bad review is not.
4. First reported quarter including the product. This is when the launch becomes numbers, and it lands on an earnings date, with everything module 4 covered.

The trading logic mirrors earnings: the reaction to each step tells you how the crowd was positioned. A stock that rallies on mediocre launch data has a low bar; one that falls on good data has a high bar. And the fundamental question is always the same: what does this product do to next year's revenue and margin, and is that already in the forward estimates?

For ACME (the industrial parent), a new product line expected to add $150M of revenue next year at a 45% gross margin, against consensus revenue growth of $240M, means the launch accounts for over 60% of expected growth. A delay of one quarter would take perhaps $40M out of next year, and analysts would cut. That arithmetic tells you how much a launch date matters before the market tells you.

For launches and other soft binaries, a stop can work if the stock is liquid and the news will not arrive as an overnight gap. The discipline is the same: date, range of outcomes, implied move if options exist, and either small enough to survive the bad end or out.

Try it: Find a small drug developer with a PDUFA date in the next 90 days (the company's IR page and free biotech calendars list them). Find the implied move from the options market. Write your own probability of approval and the resulting expected value. Then compute the maximum position size for your 1R using the worst-case outcome. Notice how small it is.

Recap

• A binary event has discrete outcomes and the stock gaps between them; a stop cannot execute.
• Size from the worst case: position = 1R ÷ worst-case loss percentage.
• FDA milestones (readouts, advisory committees, PDUFA dates) are the largest binary events for drug companies; small single-product companies move most.
• Product launches are softer binaries with an information sequence: announcement, demand data, launch, first reported quarter.
• Without a real edge in the probability estimate, trade the aftermath rather than the event.