Reading prices: ask, bid & NBBO
How to interpret the price fields the API returns.
Ask vs bid
ask is the lowest current sell offer (what you'd pay to buy now); bid is the highest standing buy order (what you'd receive selling now). The spread is ask − bid.
NBBO
National Best Bid & Offer is the best ask and best bid taken across every indexed marketplace at once, not within a single market. bestAsk and bestBid each name their source market. spreadBps expresses the spread in basis points (100 bps = 1%).
Cents, not dollars
Every price field is an integer number of USD cents, so 1550 means $15.50. Divide by 100 only at display time to avoid floating-point drift.
locked & crossed
locked is true when the best bid equals the best ask (zero spread). crossed is true when the best bid exceeds the best ask, a fleeting cross-market inversion that usually means one leg went stale a beat before the other refreshed. Both are flags so you can filter or discount those reads.