Marc Chaikin's refinement of on-balance-volume multiplies each bar's volume by a money flow multiplier that is positive when the close is near the high and negative when it is near the low, then accumulates the result.
This solves one problem with OBV: a bar that opened high, collapsed, and still closed marginally up no longer counts as full buying pressure.
It introduces its own flaw by ignoring gaps entirely. Because the multiplier uses only the current bar's own high, low and close, a stock that gaps down heavily and then closes near its high for the day registers as accumulation. Pair it with the actual price chart rather than reading it alone.
Related: on-balance-volume, chaikin-money-flow, money-flow-index, volume, divergence