DiscretionOffsetValue (FIX tag 389)

floatFIX 4.4FIX 4.2

DiscretionOffsetValue (tag 389) is a float field defined in FIX 4.4 and FIX 4.2. It appears in 8 message types, always optionally. FIX 4.2 calls this field DiscretionOffset; the tag number is unchanged, so the two are the same field on the wire.

Also known as DiscretionOffset

FIX 4.2 calls tag 389 DiscretionOffset. It is the same field on the wire — only the name changed — so a message encoded by either side interoperates.

At a glance

Tag: 389
Name: DiscretionOffsetValue
Datatype: float
Dialects: FIX 4.4 and FIX 4.2
Messages: 8

What the specification says

FIX 4.4

Amount (signed) added to the "related to" price specified via DiscretionInst (388), in the context of DiscretionOffsetType (842) (Prior to FIX 4.4 this field was of type PriceOffset)

FIX 4.2

Amount (signed) added to the "related to" price specified via DiscretionInst.

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

A real message using tag 389

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	119
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
389	DiscretionOffsetValue	1.0
10	CheckSum	105

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 389 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 4.2	Where in the message
CrossOrderCancelReplaceRequest	t	Optional	—	inside the DiscretionInstructions component
ExecutionReport	8	Optional	Optional	inside the DiscretionInstructions component
MultilegOrderCancelReplace	AC	Optional	—	inside the DiscretionInstructions component
NewOrderCross	s	Optional	—	inside the DiscretionInstructions component
NewOrderList	E	Optional	Optional	inside ListOrdGrp › DiscretionInstructions
NewOrderMultileg	AB	Optional	—	inside the DiscretionInstructions component
NewOrderSingle	D	Optional	Optional	inside the DiscretionInstructions component
OrderCancelReplaceRequest	G	Optional	Optional	inside the DiscretionInstructions component

Wire format

A decimal number. The wire form keeps its trailing zeros, which is why decoders expose the raw string alongside the parsed number. @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 389 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[389];field?.name;   // "DiscretionOffsetValue"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Other float fields

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