MIC — Market Identifier Code
A four-character code from ISO 10383 identifying an exchange or trading venue — XNYS for the New York Stock Exchange, XNAS for Nasdaq. It answers 'where' a trade or a listing happened.
- Standard
- ISO 10383
- Length
- 4 characters
- Check digit
- None — MICs are validated by registry lookup, not arithmetic
- Answers
- Where — the trading venue
- Steward
- SWIFT as registration authority
- Authoritative registry
- ISO 10383 registry (SWIFT)
- Licensing
- Open — the ISO 10383 registry is published free by SWIFT as registration authority and may be redistributed.
- Coverage in our dataset
- 48 operating MICs and 182 segment MICs
Anatomy of the code
| Part | In the example | Meaning |
|---|---|---|
| Operating MIC | XNYS | Identifies the exchange itself — here New York Stock Exchange |
| Segment MIC | ARCX | One venue inside it: NYSE Arca |
| Type flag | OPRT / SGMT | The registry marks every code as either operating or segment — the single most common source of confusion |
| Status | ACTIVE / EXPIRED | Codes are retired when venues close; expired codes still appear in historical data |
Validate one now
The validator on the Identifiers page recognises MIC automatically and checks its format in your browser — nothing is sent to a server.
Open the validator with MIC example
Questions
What is a MIC code?
A four-character code from ISO 10383 identifying an exchange or trading venue — XNYS for the New York Stock Exchange, XNAS for Nasdaq. It answers 'where' a trade or a listing happened.
What is the difference between an operating MIC and a segment MIC?
The operating MIC identifies the exchange as an institution; segment MICs identify its individual markets — order books, growth markets, derivatives venues. Nasdaq's operating MIC is XNAS, while XNGS is its Global Select Market segment. Reporting rules usually require the segment code.
Do MICs have a check digit?
No. There is no arithmetic to validate — a MIC is either in the ISO registry or it is not, which is why registry lookup is the only real validation.
Why does the same exchange have several MICs?
Because a modern exchange is a group of venues with different rules: a regulated main market, a growth market, a dark pool, a derivatives venue. Each needs to be identifiable separately for reporting.
The other identifiers
Every financial fact needs four resolutions: who (LEI), what (ISIN/FIGI/CUSIP/SEDOL), where (MIC) and in what unit (ISO 4217). The Standards page shows how they fit together; Identifiers resolves them against our data. seed-0.7 · marketcap-1 · 2026-08-30.