US Stock Identifiers Explained: CUSIP, ISIN, FIGI & Ticker

Last updated: February 2026 · 10 min read

US securities have multiple identification systems, each serving different purposes across the financial industry. From the ubiquitous ticker symbol to the regulatory CUSIP and the global ISIN, understanding which identifier to use and when is crucial for anyone working in US financial markets.

The US Identifier Ecosystem

Ticker Symbols: The Public Face

Ticker symbols are the most visible identifier but the least reliable for programmatic use. They are:

• Not unique globally: "VOD" is Vodafone on the LSE but could be something else on another exchange.
• Not permanent: Companies change tickers (Facebook → Meta changed from FB to META). Mergers, spin-offs, and rebranding all trigger changes.
• Exchange-specific: A company may trade under different tickers on different exchanges.
• Variable length: NYSE tickers are typically 1–3 characters (T, GE, IBM), NASDAQ tickers are typically 4 characters (AAPL, MSFT, AMZN).

CUSIP: The Settlement Standard

CUSIP is the backbone of US securities settlement. When a trade is executed on NYSE or NASDAQ, DTCC (the Depository Trust & Clearing Corporation) uses the CUSIP to identify the security for clearing and settlement.

CUSIP Structure

CUSIP:   037833  10  0
         ^^^^^^  ^^  ^
         |       |   |
         |       |   Check digit (modified Luhn)
         |       Issue number (10 = common stock)
         Issuer code (assigned to Apple Inc.)

Issue number conventions:

• 10 — Common stock (most frequent)
• 20, 30, etc. — Preferred stock classes
• 40+ — Corporate bonds (each new issue gets the next number)
• A0-A9 — Additional equity classes

CUSIP Licensing

CUSIPs are proprietary, owned by the American Bankers Association and operated by CUSIP Global Services (a division of S&P Global). Using CUSIPs commercially requires a license agreement. Key points:

• Redistributing CUSIP data in applications or reports requires a license
• Internal use within a single firm may have different terms
• CGS actively enforces their intellectual property rights (lawsuits have been filed)
• Alternative: Use FIGI (free) or ISIN where possible

ISIN: The Global Wrapper

For US securities, the ISIN simply wraps the CUSIP with a country code and check digit:

• ISIN = "US" + CUSIP (9 chars) + Luhn check digit
• Every US security with a CUSIP automatically has an ISIN
• Required for international settlement (Euroclear, Clearstream)
• Mandated by MiFID II for European reporting of US securities held by EU firms

US Stock ISIN Examples

FIGI: The Free Alternative

The Financial Instrument Global Identifier (FIGI) was developed by Bloomberg and donated to the Object Management Group (OMG) as an open standard. It's the only major financial identifier that's completely free to use and redistribute.

• Structure: 12 characters, always starting with "BBG" for Bloomberg-assigned FIGIs
• Granularity: FIGIs can identify not just the security but the specific listing on a specific exchange (composite FIGI vs share-class FIGI vs listing-level FIGI)
• API access: OpenFIGI.com provides a free REST API for mapping between identifiers (ticker → FIGI → ISIN, etc.)
• No licensing fees: Unlike CUSIP, you can freely redistribute FIGI data in your products

FIGI Hierarchy

Share Class FIGI:  BBG001S5N8V8  (Apple Inc. - the company)
Composite FIGI:   BBG000B9XRY4  (Apple common stock - all exchanges)
Listing FIGI:     BBG000B9Y5X2  (Apple on NASDAQ specifically)

CIK: The SEC Identifier

The Central Index Key (CIK) is assigned by the SEC to every entity that files with them. It's a 10-digit number (zero-padded) used exclusively within the EDGAR filing system.

• Apple's CIK: 0000320193
• Used in: 10-K, 10-Q, 8-K, 13F, and all other SEC filings
• Free to look up at sec.gov/cgi-bin/browse-edgar
• Not used outside the SEC/EDGAR ecosystem

Where Each Identifier Is Used

Converting Between US Identifiers

Frequently Asked Questions

Do ETFs have CUSIPs and ISINs?

Yes. ETFs are treated like any other listed security. SPY (S&P 500 ETF) has CUSIP 78462F103 and ISIN US78462F1030. The ETF's CUSIP/ISIN identifies the fund shares, not the underlying index or holdings.

Do options and futures have ISINs?

Options on US exchanges typically use OCC (Options Clearing Corporation) symbology rather than ISINs. However, listed options do have ISINs assigned for settlement purposes. Futures contracts on CME/CBOT use their own symbology but can also be identified by FIGI.

What identifier should I use in my database?

For a US-focused application: FIGI as primary key (free, stable, hierarchical). Map to CUSIP and ISIN for settlement and regulatory needs. Store tickers for display but never use them as primary keys. For international scope: ISIN as primary key with FIGI as secondary.

Why are there so many identifiers for the same stock?

Historical reasons. Each system was created by a different organization for a different purpose at a different time. Ticker symbols came from telegraph operators in the 1800s. CUSIPs were created in 1964 for settlement automation. ISINs came from ISO standardization in 1981. FIGIs from Bloomberg's open data initiative in 2009. There's no single standard because each serves a different ecosystem.