Options volume keeps setting records. In August 2026 Cboe’s S&P 500 index options traded an average of 4.63 million contracts a day, and the mini-SPX contract set a monthly record of 241,000. With that much volume, a scanner will always find a trade that looks unusual. The question is what it means. Most big prints are hedges, spread legs and closing trades. If options basics are new to you, start with the options glossary.
What is unusual options activity?
Unusual options activity is volume in an option that is far above its normal level, often several times the contract’s existing open interest. Flow scanners flag it because large, sudden trades sometimes come before news.
The usual filters are some mix of: volume above open interest, volume several times the 20-day average, a large premium paid (often $1 million or more), short time to expiry, and strikes well out of the money. Each filter catches real information sometimes. Each also catches a lot of routine institutional business: pension funds rolling hedges, market makers offsetting risk, funds closing positions before an expiry.
Why can the same trade mean four different things?
Because the tape shows the trade, not the position behind it. A 20,000-contract call purchase looks identical whether it is a fresh bullish bet or protection on a short.
- Opening bullish bet: a buyer wants upside. Open interest rises the next day and there is no matching stock or option trade.
- Hedge on a short stock position: a fund short the stock buys calls to cap its loss. The calls are bullish on paper and bearish in intent.
- Spread leg: the call is half of a call spread, risk reversal or collar. Look for a second strike printing at the same moment and size.
- Closing a short call: someone who sold calls earlier buys them back. Open interest falls the next morning.
The scanner shows all four as “large call buying.” Only the first is the story social media tells.
How do volume and open interest tell opening from closing trades?
Volume tells you a trade happened today; the change in open interest the next morning tells you whether it created new positions or closed old ones.
Open interest is the number of contracts still open after the previous day’s close, published once a day. If a series had 30,000 contracts open and 20,000 traded on Tuesday, Wednesday’s open interest settles the question. A rise to about 49,000 means the trade mostly opened positions. A fall to about 11,000 means it mostly closed them. Anything in between means a mix. That one-day wait is why intraday flow alerts can’t answer the most important question when they fire.
Don’t act on a flow alert until you’ve seen the next morning’s open interest. If open interest didn’t rise by most of the volume, it wasn’t a new bet.
How do you tell whether a trade was bought or sold?
Compare the trade price with the quote at that moment: at or above the ask suggests a buyer, at or below the bid suggests a seller, and anything near the middle is a coin flip.
Many flow tools label this for you as “ask side” or “bid side,” and they are reasonable for single-leg orders. They are unreliable for multi-leg orders, which trade as a package at a net price that may sit outside the individual legs’ quotes. A call shown as “sold at the bid” can be the short leg of a bullish spread. And as the chart below shows, even a clear call purchase can be a bearish position once you include the stock.
What are sweeps and blocks, and do they mean smart money?
A sweep is a large order split across several exchanges at once to fill quickly; a block is a single large trade, often negotiated, printed at one price. Neither proves that the trader has better information.
Sweeps signal urgency: the buyer was willing to take every available offer rather than wait. That is consistent with someone acting on news, and also with a market maker covering a position or a fund executing a hedge before the close. Blocks are the normal way institutions trade size, so they are full of hedges, rolls and spreads. “Smart money” is a label applied after the fact to the trades that worked.
What does a genuinely informative trade look like?
The cleanest directional signals combine several features at once, and that combination is rare.
| Feature | More informative | Less informative |
|---|---|---|
| Open interest next day | Rises by most of the volume | Flat or falls |
| Price | At or above the ask, single leg | Near the mid, or part of a package |
| Paired trade | None | Second strike, or stock trade |
| Expiry | Short-dated, with no scheduled event inside it | Spans earnings or a Fed meeting |
| Strike | Far out of the money | Near the money (common for hedges) |
| Size vs normal | Many times usual volume in a quiet name | Normal size for a heavily traded name |
A short-dated, far out-of-the-money call bought at the ask with no paired leg, in a name that rarely trades options, before an unscheduled announcement, is the profile regulators look at in insider-trading cases. It is also uncommon. In heavily traded names like the largest tech stocks, almost any size is normal.
Copying a flagged trade into the same short-dated option, after the price has already moved. You pay a wider spread, you have the wrong size for your account, and you don’t know if the original trader is hedged. Hype around a trade can itself be part of a pump and dump.
Is aggregate flow more useful than single trades?
Usually, yes. Aggregate measures smooth out the hedges and spreads that make single prints misleading, and they describe the market’s positioning rather than one trader’s.
Three are worth watching. The put-call ratio shows whether traders are paying for protection or upside; its extremes are contrarian signals. Skew, the price of out-of-the-money puts relative to calls, shows how much the market fears a drop. And dealer gamma exposure shows whether market makers’ hedging is likely to dampen or amplify moves near big strikes, which matters most around expiration and in the 0DTE market.
How should a long-term investor use options flow?
Use it as context for decisions you already need to make: whether protection on a position is cheap or expensive, whether positioning is crowded before earnings, whether the market is paying up for calls you could sell.
For an investor with a concentrated tech holding, heavy call buying and rising implied volatility in that stock can be a better time to sell covered calls than a reason to buy more. Heavy put buying ahead of earnings makes your own protection more expensive and suggests waiting or using a spread. In both cases the flow is a price signal about options, not a forecast about the stock.
Why does unusual activity cluster before earnings?
Because earnings are the largest scheduled risk for a single stock, so hedgers, speculators and volatility traders all position in the expiry just after the report. Volume spikes there every quarter, whatever anyone knows.
That makes pre-earnings flow the hardest to read. A surge in calls the week before a mega-cap report is usually a mix of upside speculation, call overwriters rolling, and funds buying protection on short positions. What carries more information is the price: if the straddle implies a much larger move than the stock’s recent reports, the market is paying up for uncertainty, and buying options is expensive. Compare the implied move with past reactions using the method in straddles and strangles before you read anything into the volume. The same applies to index flow before a Fed decision, covered in trading options around FOMC meetings.
What is a five-step check for any unusual options trade?
- Check the next morning’s open interest: did it rise by most of the volume?
- Check the trade price against the bid and ask, and whether it printed as part of a package.
- Look for a paired trade: a second strike, a different expiry, or stock traded at the same time.
- Compare the expiry with known events such as earnings, a Fed meeting or an index rebalance.
- Ask what it changes for you: protection cost, income opportunity or nothing. If nothing, ignore it.
Frequently asked questions
What is unusual options activity?
Unusual options activity is trading volume in an option, or in a stock’s options overall, that is far above its normal level, often volume several times larger than the existing open interest. It shows that someone traded size. It does not by itself show whether the trade was a bet, a hedge, part of a spread or a closing trade.
Does unusual options activity predict stock moves?
Sometimes, but far less reliably than it appears. Most large trades are hedges or parts of multi-leg strategies, and the cases people remember are the ones that worked. Treat unusual activity as a prompt to check news, earnings dates and positioning, not as a signal to copy the trade.
What is the difference between volume and open interest?
Volume counts contracts traded today. Open interest counts contracts still open at the end of the previous day. If volume is large and open interest rises by a similar amount the next morning, the trade mostly opened new positions; if open interest falls, it mostly closed existing ones.
What is an options sweep?
A sweep is a large order split across several exchanges at once to fill quickly at the best available prices. Sweeps suggest urgency, but market makers and hedgers use them too, so urgency doesn’t prove a directional view.
What is a block trade in options?
A block trade is a single large options trade, usually negotiated privately and printed at one price. Blocks are common for institutional hedges and multi-leg strategies, and a single block print is often one leg of a spread.
How can I tell if a trade was bought or sold?
Compare the trade price with the quote at the time: trades at or above the ask were likely initiated by a buyer, trades at or below the bid by a seller, and trades near the middle are ambiguous. Even a buyer-initiated call trade can be a hedge on a short stock position.
Key takeaways
- Unusual options activity shows that someone traded size, not why they did.
- The same large call print can be a bullish bet, a hedge, a spread leg or a closing trade.
- Next-day open interest tells you whether the trade opened or closed positions.
- Check where it traded against the bid and ask, any paired leg, and the expiry versus known events.
- Short-dated, out-of-the-money, opening, ask-side trades with no paired leg are the cleanest directional signals, and they are rare.
- Use flow as context for your own risk decisions, not as a trade to copy.
Sources and method
- Cboe, Derivatives August 2026 volume highlights — SPX ADV 4.63 million; XSP record 241,000
- Cboe, U.S. options market statistics — daily volume and put-call data
- FINRA, Options — options basics and risks
- Investor.gov, Options (glossary) — definitions of calls, puts and contracts
- Investor.gov, Pump and dump schemes — why hyped trading signals can be manipulation
Open interest and payoff charts are illustrative. The call price uses Black–Scholes with a $100 stock, a 110 strike, 30 days, 35% implied volatility and a 4.2% rate. Volume statistics are from Cboe’s August 2026 report. The four-explanation matrix is a qualitative assessment by Proflex.