Options volume

简要解答

Options volume is the number of contracts traded during a session. It resets to zero each day, which makes it a measure of activity rather than positioning — the counterpart to open interest, which carries over from day to day.

Every trade has a buyer and a seller, so volume by itself is directionless. Heavy call volume means calls traded heavily; it does not say whether the initiators were buying them or selling them, or whether they were opening new positions or closing old ones.

Options Band's volume figures come from delayed Cboe data and are summarized across the market on the activity page.

深入了解

Volume becomes more informative when read next to open interest. A worked example with round numbers:

• Monday close: a call shows open interest of 1,200 contracts.
• Tuesday: the same call trades 5,000 contracts — more in one session than existed open the day before.
• Wednesday morning: open interest prints at 4,000.

The overnight change of +2,800 says most of Tuesday's trading opened new positions rather than shuffling existing ones. Had open interest printed at 1,300 instead, the same 5,000-contract session would have been mostly closing and hand-changing. Volume alone could not distinguish the two days.

Even then, the picture stays descriptive. Those 2,800 new contracts each have a long side and a short side, and there is no public record of which side initiated. Some may be hedges against stock, legs of spreads, or rolls from another expiration. Unusual volume shows where attention concentrated on a given day; it does not reveal what the participants intend.

Context matters as much as the raw count: 5,000 contracts is a loud day for a quiet mid-cap and a rounding error for the most active tickers, so volume reads best against the same contract's own typical figures. Market-wide totals and outliers are collected on the activity page.

选读：详细说明 随堂练习不涉及此内容

Formally, daily volume is the count of contracts that changed hands during a session, with each matched trade counted once. It is reported per contract and aggregated by underlying, by type, and market-wide.

Limitations: Options Band's feed is delayed Cboe data, so intraday figures trail the tape. Multi-leg orders print leg by leg, so a single spread appears as volume in two or more strikes that were never traded independently. Rolls — closing one expiration to open another — generate volume in two contracts while leaving net exposure roughly unchanged.

Two misconceptions recur. First, that heavy call volume is bullish: every contract bought was sold by a counterparty, and the tape does not record which side initiated. Second, that volume exceeding prior open interest proves a day of net new positioning: it does mean some contracts were opened during the session, but positions opened and closed the same day leave no trace in the next morning's figure. Volume locates the activity; the change in open interest the next morning is what sizes the net result.