MarketDepth (FIX tag 264)

intFIX 4.4FIX 4.2

MarketDepth (tag 264) is an int field defined in FIX 4.4 and FIX 4.2. It appears in 1 message type and is required in 1 of them.

At a glance

Tag: 264
Name: MarketDepth
Datatype: int
Dialects: FIX 4.4 and FIX 4.2
Messages: 1

What the specification says

Depth of market for Book Snapshot

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

A real message using tag 264

MarketDataRequest · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	114
35	MsgType	V	Market Data Request
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
262	MDReqID	REQ-1
263	SubscriptionRequestType	0	Snapshot
264	MarketDepth	1
267	NoMDEntryTypes1 entry	1	repeating group
269	MDEntryType	0	Bid
146	NoRelatedSym1 entry	1	repeating group
55	Symbol	EUR/USD
10	CheckSum	009

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 264 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
MarketDataRequest	V	Required	Required	directly on the message body

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 264 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[264];field?.name;   // "MarketDepth"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