Market Data

The PAX unified market data event

PAX publishes all market data (trades, BBO, order adds and cancels) in a single unified message type, md_event_detail. Each event detail message includes the top of book [1], the quantity added to or removed from the book, and trade information [2] such as quantity bought or sold and total notional trade value.

Section	Description
tob	Best ask and bid prices and quantities, after the event.
data	Event type, side, quantity and notional value of the event, depth, and sequence number.
order	The order that triggered the event.

Note 1. The top of book is the final book state (e.g. after liquidity is removed by a trade or added by a new resting order), not the initial book state.

Note 2. There are no trade-only fields. For an EX trade, event_delta_qty and event_total_px are the quantity traded and its notional value, as negative numbers. For an XA, they also include the quantity that rests; see Book Building. For other events, the same fields describe the quantity added or canceled.

PAX tick-based prices and integer quantity units

PAX uses integer values for price and quantity. Price is in tick units. Quantity is scaled from the base asset’s native units. Market metadata is available at GET /v1/metadata/exchange-info; see Markets and Data Formats.

Market	Tick size	Qty unit
BTC-USDC	1 USDC	1 satoshi	(10⁻⁸ BTC)
ETH-USDC	0.1 USDC	1 gwei	(10⁻⁹ ETH)
SOL-USDC	0.001 USDC	1 lamport	(10⁻⁹ SOL)

See Subscribing, Message Details, and Book Building.