NBBO stands for National Best Bid and Offer.
What it means
The NBBO represents:
- Best Bid: The highest price any buyer is currently willing to pay
- Best Offer: The lowest price any seller is currently willing to accept
These prices are aggregated across all U.S. exchanges.
Why it matters
Regulations require brokers to execute your trades at prices equal to or better than the NBBO. This ensures you get competitive pricing.
How Aries uses NBBO
When you place a market order, Aries routes your order to seek the best available price. For marketable orders, execution should be at or better than the NBBO at the time of order receipt.
Price improvement
Sometimes orders execute at prices better than the NBBO—this is called price improvement. Aries tracks and reports price improvement statistics.