What is Quote stability (quote flicker)?

Quote stability describes how long a displayed bid or ask remains in place before it updates or cancels. Frequent, rapid changes without trades are called quote flicker and indicate unstable books.

Stability varies by venue, asset, and market conditions and is a key signal for execution tactics.

Why quotes flicker

Flicker can result from competing market makers reacting to each other, latency asymmetry, and microstructure rules like maker protection. During stress, wide spreads and defensive quoting accelerate churn.

Low tick sizes and aggressive step-ahead behavior also contribute to rapid updates.

Effects on routing and risk

Unstable quotes increase the chance of missing intended prices and raise queue risk. Passive orders may get canceled around, while aggressive orders may chase moving targets, increasing slippage.

Routing to venues with steadier quotes can improve completion rates and reduce adverse selection.

Measurement nuances

Stability is quantified by dwell times, update rates, and the fraction of updates without trades. Clean measurement needs synchronized data and filters for crossed or locked markets to avoid false signals.

Comparisons should be segmented by time of day and volatility to control for regime differences.

Things to Remember

• Churn is costly: High flicker harms both passive and aggressive tactics.
• Segment intelligently: Compare stability by asset, venue, and regime.
• Prefer steadier books: Routing to stable venues often improves outcomes.
• Measure carefully: Dwell times and no-trade updates need clean, synced data.