as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
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comparing option data between yahoo finance and cboe for spy options
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the cboe site, as well as some other sites and trading platforms, will show the bid/ask and statistics for that option at each individual options exchange, in addition to statistics and the best bid/offer across all exchanges. cboe.com: delayed quote help lists what the single-letter codes mean. a is for the amex options exchange, b is for box, x is for phlx, etc.
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