Options Flow, Dark Pool and GEX Glossary
This glossary explains the terms you meet in Robinflow and across options flow, dark pool and gamma exposure data. Each page opens with a one-sentence definition, explains why the term matters, and spells out what the number cannot tell you, because most of these figures are easier to misread than to read.
Every page also carries a worked example taken from Robinflow's own data: a real ticker, a real session and the values as the app displayed them. Examples built on individual trades are at least three sessions old, and the public symbol pages the aggregates come from are three sessions delayed, so nothing here is a live signal. The terms are grouped the same way the product is: options flow, dark pool activity and GEX. Read a group in order for a short course, or jump straight to the term you need.
Options flow
Options flow is the stream of option trades printing across the U.S. exchanges, with each fill’s size, price and where it traded against the quote. These terms cover how a trade executes and how to read its size against what was already open.
- Options SweepAn aggressive order routed across several exchanges at once to fill quickly, taking every contract available at the price.
- Block TradeA large options order executed as a single print, often negotiated privately and reported as one trade.
- At the Ask vs At the BidWhere a trade printed against the quote: at the ask means the buyer was aggressive, at the bid means the seller was.
- Volume to Open Interest RatioA contract's day volume compared with the open interest that existed before the session; above 1, more contracts traded than were open.
- Multi-Leg Options TradeOne order made of two or more option contracts traded together as a package, such as a spread, shown on Robinflow as a single expandable row with its net debit or credit.
Dark pool
Dark pool prints are large stock trades executed away from the public exchanges and reported to the tape afterwards. These terms cover a single print, the price levels that repeated prints build up, and the condition codes attached to a report.
- Dark Pool PrintOne executed stock trade in a dark pool, reported to the public tape after it happens: time, size, price and dollar value.
- Dark Pool LevelsPrices where significant dark pool volume printed in one stock; levels below the current price read as support, above it as resistance.
- Trade Condition Codes on Dark Pool PrintsFlags on a stock print that mark it as a bookkeeping report, such as an average-price trade, a late report or a contingent trade, rather than a live block.
GEX
Gamma exposure describes how much hedging options dealers must do as price moves, and in which direction. These terms cover the exposure figure itself, the difference between a positive and a negative gamma regime, and the strikes where the hedging is heaviest.
- Gamma Exposure (GEX)An estimate of how much stock options market makers must buy or sell to stay hedged as price moves, mapped by strike.
- Positive vs Negative GammaIn a positive gamma regime dealer hedging leans against price moves; in a negative regime it leans with them.
- Call WallThe strike where positive net gamma exposure is heaviest, usually because of the call open interest sitting there.
- Put WallThe strike where negative net gamma exposure is heaviest, usually because of the put open interest sitting there.