BidSize (FIX tag 134)

QtyFIX 4.4FIX 4.2

BidSize (tag 134) is a Qty field defined in FIX 4.4 and FIX 4.2. It appears in 5 message types, always optionally.

At a glance

Tag
134
Name
BidSize
Datatype
Qty (float)
Dialects
FIX 4.4 and FIX 4.2
Messages
5

What the specification says

Quantity of bid (Prior to FIX 4.2 this field was of type int)

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

A real message using tag 134

Quote · FIX 4.4
TagFieldWire valueMeaning
8BeginStringFIX.4.4
9BodyLength87
35MsgTypeSQuote
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
117QuoteIDEXAMPLE
134BidSize1000000
10CheckSum225
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 134 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.

MessageMsgTypeFIX 4.4FIX 4.2Where in the message
MassQuoteiOptionalOptionalinside QuotSetGrp › QuotEntryGrp
MassQuoteAcknowledgementbOptionalinside QuotSetAckGrp › QuotEntryAckGrp
QuoteSOptionalOptionaldirectly on the message body
QuoteResponseAJOptionaldirectly on the message body
QuoteStatusReportAIOptionaldirectly on the message body

Wire format

A decimal quantity. Fractional quantities are legal, which is why this is a float family rather than an integer. @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 134 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[134];field?.name;   // "BidSize"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Other Qty 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