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Key Takeaways
- An at-bid print matches the displayed buying quote at execution.
- Hitting the bid means a sell order executes against displayed buying interest.
- Calculate gross premium from price, quantity and the contract multiplier.
- Evaluate option type, opening or closing action and every leg in the package.
- Connect the execution with contract activity, implied volatility and underlying price.
What is a trade at the bid?
A trade at the bid is an execution whose price matches the displayed bid, the buying price, in the quote in effect at that moment. A sell order that takes that price is described as hitting the bid, and it takes liquidity from the displayed buyer. An at-bid print locates the execution price; the option type, position effect, and related legs determine the exposure.
Compare trade price with the quote in effect at execution. For an exact at-bid match, execution equals bid. A fill inside the spread lands between the two: the example’s $4.64 fill scores 0.80.
Formula
Bid proximity = (ask − execution price) / (ask − bid)- A value of 1.00 locates the execution at the bid; 0.50 locates it at the midpoint.
- Use the execution-time quote with ask greater than bid.
- An exact opposite-side execution gives 0.00.
At-bid trade example: premium and bid proximity
An XYZ put is quoted $4.60 bid and $4.80 ask when 700 contracts execute at $4.60.
- Bid: $4.60
- Ask: $4.80
- Execution: $4.60
- Gross premium: $322,000 using a 100 multiplier
- Bid proximity: 1.00
The 700-contract execution matches the $4.60 bid and carries $322,000 of gross premium. A seller took the bid on those puts; the position effect and related legs show whether it opened a bullish short put or closed a long one.
Bid proximity equals ($4.80 − $4.60) ÷ ($4.80 − $4.60) = 1.00. An execution at $4.64 in that market scores 0.80. Midpoint execution at $4.70 scores 0.50.
The 700-contract fill takes every contract bid at $4.60 and clears the level. A larger sell drops to the 180 contracts bid at $4.55 only if its limit allows.
How an at-bid print fits the full position
Selling a call to open creates negative option delta. Selling a put to open creates positive option delta. Selling to close removes a long option. Include every related leg before calculating the complete exposure.
A short higher-strike call paired with a long lower-strike call at the same expiration forms a bull call spread, opened for a debit. A short lower-strike call paired with a long higher-strike call forms a bear call spread, opened for a credit. The strike arrangement determines the payoff.
How traders read at-bid activity
Use options flow to inspect premium, quantity, execution conditions and related contracts. Compare the underlying chart, implied volatility and contract concentration at the strikes and expirations in play. The options profit calculator then prices the complete position’s entry cash and dollar outcomes at the price levels and dates in the trading plan.
Limitations of at-bid classification
- Confirm the position effect before you call it bearish. An at-bid call can close a long call or be the short leg of a bull call spread, and an at-bid put sold to open adds positive delta.
- Score each print against the quote at its execution time. Quotes change within milliseconds, and a delayed quote can move the same print from the bid to the inside of the spread or the ask.
- Net the package before you read a leg. In a multi-leg order the exchange allocates leg prices to meet the package’s net price, so one leg can print at the bid while the package trades for a debit.
- Score only against an execution-time quote with the ask above the bid, and set aside prints against a locked or crossed quote.
- Add up the prints before you size the order. Each print shows the quantity that traded at one level, and a larger order can fill across several.
Bottom line
When 700 puts trade at the $4.60 bid, a seller has hit the buyers. Read the option type, the position effect, and the related legs to see whether the trade added bearish exposure, added bullish exposure, or closed a position.
Clear answers
Frequently Asked Questions
Sources and Further Reading
How entries are sourced, calculated and updated: editorial methodology.