Unusual options activity is trading in an option contract that is far larger than normal for that contract, most often measured as the day's volume divided by its open interest. When volume is several times the existing open interest, much of the trading is likely to be new positions rather than old ones being closed.
How it works
Open interest is the number of contracts already open at the start of the day (see open interest vs volume). If a contract with 1,000 open trades 6,000 in a session, most of that volume cannot have been closing out positions that existed in the morning, because there were not enough of them. A large share is therefore likely to be new, although some may be positions opened and closed within the same day. Screens therefore rank contracts by:
- Volume ÷ open interest. The higher the ratio, the more the day's trading exceeds existing positioning. Ratios above 2 are a common starting threshold.
- A minimum size. A floor such as 500 contracts filters out small trades in illiquid strikes, where a ratio of 10 can mean 50 contracts.
- Premium. Volume × price × 100 gives the dollars committed, which separates a $20,000 trade from a $2 million one.
Beyond these numbers, useful context includes whether trades printed near the ask (buyer-initiated) or the bid (seller-initiated), whether they came as one large block or as a sweep across several exchanges, how far out of the money and how close to expiry the contract is, and whether implied volatility rose with the buying.
How to read it
- The usual lean. Heavy call buying is read as bullish and heavy put buying as bearish. Treat this as a hypothesis, not a conclusion.
- Short-dated, out-of-the-money buying is the most speculative kind; longer-dated or in-the-money activity is more often part of a hedge or a stock replacement.
- Event timing. Activity concentrated in the first expiry after earnings or a scheduled decision is often a bet on, or a hedge against, that event. Those options also carry event volatility that tends to fall after the news (see IV crush).
- Confirmation. Check the next day's open interest. If it rose by roughly the volume, positions stayed open; if not, the trades may have been opened and closed within the day.
- The stock itself. Option activity alongside unusual volume in the shares carries more weight than options alone.
Worked example (illustrative numbers)
A stock trades at $60. Its $65 call expiring in three weeks starts the day with open interest of 1,000 and trades 6,000 contracts at an average of $1.50.
| Measure | Value |
|---|---|
| Volume ÷ open interest | 6,000 ÷ 1,000 = 6× |
| Premium | 6,000 × $1.50 × 100 = $900,000 |
| Next morning's open interest | 5,200 (up 4,200) |
The flow clears a 500-contract, 2× threshold, and the next day's open interest confirms that most of it stayed open. That still leaves several explanations: an outright bullish bet, the long leg of a spread whose short leg sits at another strike, a fund buying calls against a short stock position, or a dealer-facilitated trade where the customer sold rather than bought. Each implies something different about direction.
Limitations and common mistakes
- Volume does not show who initiated. Every trade has a buyer and a seller; a screen may not tell you which side was the customer.
- Hedges and spreads look like bets. A put bought to protect a large stock holding is not a bearish forecast, and one leg of a multi-leg trade can look unusual on its own.
- Events make heavy volume normal. Before earnings, high ratios are common and less informative.
- Many unusual trades lose money. Large or well-informed traders are wrong too, and copying flow without a plan for risk is not a strategy.
- Delayed data loses the edge. By the time end-of-day flow is published, the stock and the option's price may already have moved.
In Clear Tape
Pro members can see an Unusual flow table on the Options page for any stock with listed options. It lists contracts that traded 500 or more contracts and more than twice their open interest, with volume, open interest, volume ÷ open interest, IV and premium, alongside put/call ratios on both volume and open interest. The analysis notes when such contracts appear, and the watchlist scan shows the number of unusual contracts and their total premium for each stock. Members see each session's closing data once the next session has opened, so the table describes the previous session, not live flow. See pricing.
For educational purposes only. Not investment advice.