Taker delay

Marketable orders are held briefly before matching — 500ms by default, 3s on sports markets during match time.

XO holds marketable (taking) orders for a short window before they match. This gives resting makers time to update quotes and reduces temporal arbitrage against stale liquidity.

Resting maker orders that do not cross the book on arrival are not delayed.

Delay windows

Scope	Delay
All markets (default)	500 ms
Sports markets during match time	3 s

Outside match time, sports markets use the default 500 ms window.

What gets delayed

An order is held when it would take liquidity on arrival:

Arrival behavior	Delayed?
FAK / FOK	Always
GTC / GTD priced through the spread (would match immediately)	Yes
GTC / GTD that rests without crossing	No

Classification is by book-crossing behavior, not by time-in-force alone. A GTC that crosses the spread is delayed the same way as an FAK.

HTTP behavior

POST /order and POST /orders block for the delay window plus matching. The response carries the final outcome (matched, live, or a rejection) after the hold completes — you do not poll for a mid-window status.

Budget request timeouts accordingly: at least 500 ms on non-sports markets, and at least 3 s when taking into sports markets that are in match time.

Sports match-time override

When a sports event is live (match time), the orderbook raises the taker delay for that event’s CLOB markets to 3 seconds. When match time ends, those markets fall back to the default 500 ms.