FIBO is missing the concept of National Best Bid and Offer (NBBO)

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See https://www.investopedia.com/terms/n/nbbo.asp "The National Best Bid and Offer (NBBO) is a Securities Exchange Commission (SEC) regulation requiring brokers to trade at the best available (lowest) ask price and the best available (highest) bid price when buying and selling securities for customers. The National Best Bid and Offer is the bid or ask price that the average customer will see. "