• NBBO shows the best available (lowest) bid price and the best available (highest) bid price available to clients from multiple exchanges.

  • The SEC regulation NMS requires brokers to guarantee their clients at least the quoted price of NBBO at the time of a trade.
  • NBBO is calculated and distributed by Security Information Processors (SIPs).
  • While this ensures that all investors receive the best possible prices when making trades, the NBBO may not always reflect the latest data, resulting in trades that may not match investors’ price expectations.