TotNoRelatedSym (FIX tag 393)

intFIX 4.4FIX 4.2

TotNoRelatedSym (tag 393) is an int field defined in FIX 4.4 and FIX 4.2. It appears in 3 message types and is required in 1 of them. FIX 4.2 calls this field TotalNumSecurities; the tag number is unchanged, so the two are the same field on the wire.

Also known as TotalNumSecurities

FIX 4.2 calls tag 393 TotalNumSecurities. It is the same field on the wire — only the name changed — so a message encoded by either side interoperates.

At a glance

Tag: 393
Name: TotNoRelatedSym
Datatype: int
Dialects: FIX 4.4 and FIX 4.2
Messages: 3

What the specification says

FIX 4.4

Total number of securities. (Prior to FIX 4.4 this field was named TotalNumSecurities)

FIX 4.2

Total number of securities.

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

A real message using tag 393

DerivativeSecurityList · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	100
35	MsgType	AA	Derivative Security List
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
320	SecurityReqID	EXAMPLE
322	SecurityResponseID	EXAMPLE
560	SecurityRequestResult	0	Valid request
393	TotNoRelatedSym	1
10	CheckSum	255

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 393 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
BidRequest	k	Required	Required	directly on the message body
DerivativeSecurityList	AA	Optional	—	directly on the message body
SecurityDefinition	d	—	Required	directly on the message body
SecurityList	y	Optional	—	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 393 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[393];field?.name;   // "TotNoRelatedSym"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