The bid and ask prices for stock options are not the same due to how option payoffs are distributed. In the Chicago Board of Options Exchange, the bid price is closer to the option value than the ask price. This difference increases for options that are further from being "in the money". Additionally, the ask price of an option changes more than the bid price. This means that the midpoint between the bid and ask prices may not accurately represent the true value of the option, especially for options that are "out of the money". It's important to be careful when interpreting trade prices compared to the most recent bid and ask prices.