A stock I hold went down heavily today. I found a November call option for pretty cheap, though it had a relatively large bid and ask spread. It also had low (or zero, I don't remember) open interest. I picked a number between the buy and ask prices, and created a limit order for one contract.

To my surprise, the order filled within a few minutes. Was this luck, or could I have expected this order to be filled?

2 Answers 2


An option's fair value is somewhere in the vicinity of the mid-price between the bid & ask.

B/A spreads widen during volatile periods. They also widen for stocks that have a low trading volume and options with low liquidity. If there is no interest in the option at a given moment in time, the market maker will widen the spread and it will stay there until someone places and order with a better bid or ask. Why should the market maker offer anything competitive if he doesn't have to? Plus, some noob who doesn't know any better might come along and pay the full ticket.

You came along and made an offer to buy near the midpoint. Either the market maker or another counter party was willing to transact at that price. It's that simple.


Brokers can take requests in person. It’s possible that someone registered an interest in a position that made them ideal as your counterparty.

It’s also possible that someone tracking the lists saw your order and decided that as there wasn’t any other activity, this was as good as they were going to get.

The lists represent what the market has keyed into the system. But they don’t represent all of the intentions of the market’s interested parties.

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