SideLastQty (FIX tag 1009)

intFIX 5.0 SP2

SideLastQty (tag 1009) is an int field defined in FIX 5.0 SP2. It appears in 2 message types, always optionally.

At a glance

Tag: 1009
Name: SideLastQty
Datatype: int
Dialects: FIX 5.0 SP2
Messages: 2

What the specification says

Used to indicate the quantity on one side of a multi-sided trade.

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 1009

TradeCaptureReport · FIX 5.0 SP2

Tag	Field	Wire value	Meaning
8	BeginString	FIXT.1.1
9	BodyLength	116
35	MsgType	AE	TradeCaptureReport
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
32	LastQty	1000000
31	LastPx	1.09210
552	NoSides2 entries	2	repeating group
54	Side	1	Buy
1009	SideLastQty	1
54	Side	1	Buy
1009	SideLastQty	1
10	CheckSum	160

Edit and decode it yourself

Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.

Open in the full decoder →

Generated from the FIX 5.0 SP2 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 1009 appears

Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.

Message	MsgType	Requiredness	Where in the message
TradeCaptureReport	AE	Optional	inside the TrdCapRptSideGrp component
TradeCaptureReportAck	AR	Optional	inside the TrdCapRptAckSideGrp component

Wire format

A whole number, optionally signed. Leading zeros are legal on the wire and are preserved in the raw value. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 1009 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix50sp2";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[1009];field?.name;   // "SideLastQty"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Decode this in your own code

The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.

npm i @boarteam/fix @boarteam/fix-dict-fix50sp2

Try the decoder Source on GitHub