Market Data Engineering

Crossed/Locked Market Detector Lab

Compare exact spread geometry with an explicitly configured tick-fraction tolerance. The raw spread, exact state, and source context remain visible even when the configured label changes.

Synthetic educational data - not a historical NBBO interval

Signed spread in ticks

Exact and configured crossed/locked market classifications A signed-spread chart shows synthetic quote observations around zero. Point color gives exact state and a purple square marks when configured tolerance changes the label.
Exact normal Exact locked Exact crossed Configured label differs

Recent observations

SeqEvent timeSide sourcesBidAskSpread ticksExactConfigured

Keyboard: Left Arrow = Back, Right Arrow = Step, Space = Play/Pause, R = Reset. Reduced-motion mode makes Play advance one deterministic step.