US Stock Ticker Symbol Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching us stock ticker symbol, ported and verified for JavaScript. 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 JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// US Stock Ticker Symbol
// ReDoS-safe | RegexVault — Finance > Securities & Trading

const usStockTickerSymbolRegex = /^[A-Z]{1,4}(?:\.[A-Z]{1,2})?$/;

function validateUsStockTickerSymbol(input: string): boolean {
  return usStockTickerSymbolRegex.test(input);
}

// Example
console.log(validateUsStockTickerSymbol("AAPL")); // 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 JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. 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

NYSE: 1-3 characters. NASDAQ: 4 characters. The suffix (.A, .B, .PR, .WS) indicates share class, preferred, or warrant. Different exchanges use different conventions.