Inside the exchange — one order, matched in microseconds
one order · ambient traffic pausedorders inmarket datatrades / fillsrisk / surveillanceAn order leaves a co-located trading member — one of thousands of authenticated sessions — and arrives at the order-entry gateway, the only door in. Follow this single order to a matched trade.
Trace mode. The ambient traffic is paused so you can follow exactly one order — and every module it touches. Press next ▸ to walk it: a member order is validated and sequenced, the matching engine shards it to the order book and crosses it; a trade prints to clearing and a private ack returns, then the book change is disseminated to the whole market, with circuit breakers and surveillance watching. Switch to Live traffic to see it all at once. Hover any module for its job and exact data in/out.
zoom in
The overview shows the whole venue. Here the two stages that decide fairness and price are opened up into their own sub-components, animated with the actual work each one does — step through them.
Every order passes a pipeline of small gates before it can be matched. The sequence-assign step — a single atomic counter — is the fairness the exchange can never take back: it fixes your place in the queue.
The order gate is a pipeline of small, independent sub-components. Watch one order pass through each — and where the sequencer stamps the fairness it can never take back.
read frame · identify member
binary → order fields
segment / instrument allowed?
per-session token bucket
within the day's band?
under the freeze size?
value & tick / lot valid?
member exposure & margin
atomic monotonic counter ++
hardware clock · nanoseconds
inbound ring · per shard
confirm back to member
sequence #
4,80,191
PTP timestamp
—
inbound ring → matching shard
The cycle the engine runs for every order: marketability → price-level lookup → FIFO front → cross & fill → trade generate → book update → walk-or-rest → market-data emit. Watch the live order book mutate at each sub-step.
The matching loop is a tight cycle of sub-components. Watch one aggressive order run the cycle until it is filled.
does it cross best opposite?
bitmap index → best level
oldest order at the level
min(qty) trades
price · qty · ids · ts
pop filled · update totals
next level, or rest in queue
publish change + trade
price · queue (oldest first →)asks
bids
An exchange is, at its core, one machine: a matching engine that keeps a central limit order book for every instrument and crosses orders by strict price-time priority. Members send orders over authenticated sessions; the exchange validates them, stamps each with a sequence number and timestamp, matches them in microseconds, prints trades, hands them to clearing, and broadcasts every change to the whole market at the same instant. The animation above traces one order through that whole path — the venue's own engine, not a trading firm's.