Polymarket Tick-Size Changes: Preventing Invalid Prices and Broken Quotes

Tick size is runtime market metadata and must not be hard-coded into a quoting engine.

Model the failure correctly

Represent prices as exact decimals and apply documented, side-aware rounding without crossing an economic limit.

Collect evidence

Version every quote generation with the tick size and book snapshot used to create it.

Build the control path

Refresh authoritative metadata and invalidate in-flight generations when the increment changes.

Handle edge cases

Cancel nonconforming orders deliberately, reconcile partial fills, then quote from a fresh book.

Recovery procedure

Test near-zero and near-one prices, half ticks, minimum size, reconnects, and changes during submission.

Production metrics

Expose current tick, metadata age, rounding adjustments, and invalid-price rejects in the dashboard.

TierZero can help implement or review this architecture through our relevant engineering service.

Primary reference

See the official technical documentation and pin the exact API behavior used by your deployment.

Discuss your system with TierZero.