Last Look

Last look is a practice in which a liquidity provider, after receiving a trade request against its streamed price, takes a brief moment to decide whether to accept or reject it. The window is typically a few milliseconds and exists because prices are streamed to many clients at once and can move during transmission. From the trader's side, last look shows up as rejections or requotes rather than instant fills, particularly around news events. Regulators and industry codes of conduct have pushed for clear disclosure of last-look policies and for the window not to be used to trade on client information. Venues that execute without it are usually described as firm-liquidity or no-last-look.