Retail Price Improvement (RPI) Orders are designed to improve the bid/ask spread for retail users on the trading interface. They allow selected market makers to quote more competitive prices to retail users, while preventing algorithmic traders from accessing these quotes.
Key Features
Exclusive Matching: RPI orders only match with non-algorithmic (UI) users. Orders placed via API cannot match with RPI.
Post-Only: RPI orders always add liquidity and cannot take liquidity from the order book.
Lowest Execution Priority: RPI orders are executed only after all non-RPI orders at the same price.
Visible on UI: RPI orders appear on the trading interface but are excluded from the API order book and market data.
Matching Rules
RPI orders cannot cross or match with non-RPI resting orders at time of placement.
RPI orders can cross with other RPI orders, but not match them.
UI taker orders can match resting RPI orders.
RPI orders do not interact with orders placed via OpenAPI.
Example behavior:
Resting Order | Arriving Order | Outcome | Reason |
GTT | RPI | Reject | RPI cannot cross non-RPI |
RPI | GTT (UI) | Match | UI user can hit RPI |
RPI | GTT (API) | No Match | API orders can’t hit RPI |
RPI | RPI | Enter Book | RPI can cross but not match RPI |
Trading Rules
Available on all trading pairs and margin modes
Same price limits and order size constraints as standard limit orders
Cannot be combined with conditional orders (e.g., stop-loss, take-profit)
RPI orders must be limit + post-only + API-sourced
Order Book Visibility
UI Interface: RPI orders are visible if not crossed
API Order Book: RPI orders are excluded
Crossed Orders: Hidden from UI to preserve uncrossed book view
Logged-out Users: Cannot see RPI orders
Crossed RPI orders remain active in the matching engine but are hidden from the displayed order book.
Technical Notes
New TIF (Time in Force) value: RPI
Rate limit: 240 createOrder requests/hour for non-API users
New
rpi.book.snapandrpi.book.deltastreams available for UI sources only
Impact on Market Data
RPI orders are excluded from impact price and funding rate calculations
Ticker best bid/ask does not include RPI orders
For additional specifications and implementation details, contact support.