Market Identifier Code (MIC) Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching market identifier code (mic), ported and verified for Go. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// Market Identifier Code (MIC)
// ReDoS-safe | RegexVault — Finance > Securities & Trading

package validation

import "regexp"

var marketIdentifierCodeMicRe = regexp.MustCompile(`^(?!NYSE$)[A-Z0-9]{4}$`)

func ValidateMarketIdentifierCodeMic(s string) bool {
    return marketIdentifierCodeMicRe.MatchString(s)
}

// Example
// fmt.Println(ValidateMarketIdentifierCodeMic("XNYS")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Securities & Trading category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

ISO 10383 MICs: XNYS=NYSE, XNAS=NASDAQ, XLON=LSE, XTKS=TSE Tokyo, XHKG=Hong Kong, XSES=SGX Singapore. The X prefix denotes the primary/regulated market. S prefix for segments.