Starbase - Trades (Upcoming)

This page describes market data schema version 2 (semantic version 1.0), which is live on testnet and goes live in production on 10 November 2026. Download the testnet market data XML. See the Starbase changelog.

Trades

Trade Summary (30)

This message is sent when a taker order matches against one or more maker/resting orders, followed by one or more Trade messages.

Field	Name	Type	Length	Description
1	instrumentId	int64	8	Numeric instrument ID
2	takerOrderId	int64	8	Unique identifier for the taker order
3	totalFilledMantissa	QuantityMantissa	8	Total amount filled (by the taker order)
4	deepestPrice	Price9	8	Deepest price in book matched by taker order
5	markPrice	Price9	8	Mark price at the time of the trade
6	indexPrice	Price9	8	Index price at the time of the trade
7	tradeCount	int32	4	Number of Trade messages that will follow this message
8	takerFlags	uint32	4	Attributes of taker order, defined below

The table below outlines the content of TradeFlags: field 8 (takerFlags) in Trade Summary, field 6 (makerFlags) in Trade and field 10 (takerFlags) in Block Trade:

Bit number (from last to first)	Name	Description
1	isSell	`0`=Buy `1`=Sell
2	isLiquidation	`0`=Not a liquidation `1`=Liquidation trade
3	wasDelayed	`0`=Published at execution `1`=Block trade published after a delay. Added in schema version `2`. Set only on Block Trade (33) messages; see Delayed block trades
4	Reserved for future use
5	Reserved for future use
6	Reserved for future use
7	Reserved for future use
8	Reserved for future use

Trade (31)

This message is sent for each matched order (including implied orders) and synthetic leg for trades on combo instruments.

Field	Name	Type	Length	Description
1	matchId	int64	8	Unique identifier of the trade
2	instrumentId	int64	8	Numeric instrument ID
3	makerOrderId	int64	8	Unique identifier for the resting order. In case of implied order or synthetic leg of a combo trade, encoded as `0x8000000000000000`
4	amount	QuantityMantissa	8	Amount that was matched
5	price	Price9	8	Price at which the match occurred
6	makerFlags	uint32	4	See table above

Block Trades

Block Trade (33)

This message is sent for each individual trade in a block trade. Multiple Block Trade messages belonging to the same block trade event are grouped as a transaction via the startOfTransaction and endOfTransaction flags in the message header. A block trade event is per instrument: a multi-leg block trade generates one transaction per leg. For example, a Block RFQ with 3 legs where the taker trades against 2 makers produces 3 transactions, each containing 2 Block Trade messages. Block RFQ trades include a blockRfqId; standard block trades omit it. From schema version 2 the message body is 88 bytes (previously 78). Fields 12 and 13 are appended at the end of the message, so earlier fields keep their offsets. With the 16-byte message header and padding to an 8-byte boundary, messageLength in the message header is 104 (previously 96).

Field	Name	Type	Length	Description
1	matchId	int64	8	Unique identifier of the block trade fill
2	instrumentId	int64	8	Numeric instrument ID
3	blockTradeId	int64	8	Per-fill block trade identifier assigned by the matching engine
4	blockRfqId	int64	8	Block RFQ identifier; absent (null value) for standard block trades, present for Block RFQ trades
5	fillQtyMantissa	QuantityMantissa	8	Fill quantity
6	fillPrice	Price9	8	Price at which the block trade occurred
7	markPrice	Price9	8	Mark price at the time of the block trade. On a delayed print, the mark price at execution
8	indexPrice	Price9	8	Index price at the time of the block trade. On a delayed print, the index price at execution
9	impliedVolatility	double	8	Implied volatility; absent (null value) for non-option instruments
10	takerFlags	uint32	4	Attributes of the taker side; see flags table in Trades section above
11	numberOfLegs	uint16	2	Total number of legs in the block trade structure
12	padding2	int16	2	Padding; ignore. Added in schema version `2`
13	executionTimestamp	TimestampNanos (int64)	8	Nanoseconds since epoch. Execution time of the block trade. Set only when `wasDelayed`=`1`; otherwise null value (`0x8000000000000000`). Added in schema version `2`

Delayed block trades

Qualifying Block RFQ trades can have their public publication delayed. The eligibility rules, size thresholds and delay are the same as for the JSON-RPC API; see the JSON-RPC API Changelog. A delayed block trade is not published on the incremental channel at execution. When the delay ends, its Block Trade messages are published with:

wasDelayed set in takerFlags
executionTimestamp set to the execution time
transactTime in the message header set to the publication time
the original matchId, blockTradeId, blockRfqId, prices and quantities from execution

Block trades that are not delayed are published at execution as before, with wasDelayed=0 and a null executionTimestamp; transactTime is the execution time.

Introduction

API Reference

Core Concepts

Technical Information

Trades (Upcoming)

Trades

Trade Summary (30)

Trade (31)

Block Trades

Block Trade (33)

Delayed block trades

​Trades

​Trade Summary (30)

​Trade (31)

​Block Trades

​Block Trade (33)

​Delayed block trades

Trades

Trade Summary (30)

Trade (31)

Block Trades

Block Trade (33)

Delayed block trades