ParticipationRate (FIX tag 849)

PercentageFIX 4.4FIX 5.0 SP2

ParticipationRate (tag 849) is a Percentage field defined in FIX 4.4 and FIX 5.0 SP2. It appears in 8 message types, always optionally.

At a glance

Tag: 849
Name: ParticipationRate
Datatype: Percentage (float)
Dialects: FIX 4.4 and FIX 5.0 SP2
Messages: 8

What the specification says

FIX 4.4

For a TargetStrategy=Participate order specifies the target participation rate. For other order types this is a volume limit (i.e. do not be more than this percent of the market volume)

FIX 5.0 SP2

For a TargetStrategy=Participate order specifies the target particpation rate. For other order types this is a volume limit (i.e. do not be more than this percent of the market volume)

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

A real message using tag 849

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	120
35	MsgType	D	Order – Single
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
849	ParticipationRate	0.05
10	CheckSum	150

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 4.4 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 849 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	FIX 4.4	FIX 5.0 SP2	Where in the message
CrossOrderCancelReplaceRequest	t	Conditional	Optional	directly on the message body
ExecutionReport	8	Conditional	Optional	directly on the message body
MultilegOrderCancelReplace	AC	Conditional	Optional	directly on the message body
NewOrderCross	s	Conditional	Optional	directly on the message body
NewOrderList	E	Conditional	Optional	inside the ListOrdGrp component
NewOrderMultileg	AB	Conditional	Optional	directly on the message body
NewOrderSingle	D	Conditional	Optional	directly on the message body
OrderCancelReplaceRequest	G	Conditional	Optional	directly on the message body

Wire format

A decimal rate where 1.0 means 100%, not 1%. @boarteam/fix parses the value as a number and reports parse/invalid-float when it does not lex as one; the raw string is kept so precision and trailing zeros are never lost.

Read tag 849 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix44";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[849];field?.name;   // "ParticipationRate"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-fix44

Try the decoder Source on GitHub