What is a CUSIP?
TL;DR
A CUSIP is the 9-character identifier that uniquely names a North American security (stocks, bonds, options, warrants, ADRs, etc.). Structure: 6-char issuer prefix + 2-char issue identifier + 1-char check digit. Every Form 13F line item must include the CUSIP — it's the SEC's primary key for unambiguous identification. Tickers are not unique enough; CUSIPs are.
CUSIP stands for Committee on Uniform Securities Identification Procedures. The committee was established in 1964 by the American Bankers Association to solve a back-office crisis: paper securities settlement was failing because there was no shared way to name a security across institutions. The 9-character identifier the committee published is now the U.S. and Canadian financial-system standard.
The anatomy of a CUSIP
Every CUSIP has three parts. Using Apple's common stock CUSIP 037833100 as an example:
- 037833 — issuer prefix. Assigned to Apple Inc. for life. Used across all Apple-issued securities (common stock, preferred, bonds, options chains). 6 alphanumeric characters (digits + uppercase letters, no I or O to avoid 1/0 confusion).
- 10 — issue identifier. Distinguishes among Apple's issued securities.
10is the common stock; bond issues and preferred series get sequential issue identifiers. - 0 — check digit. Calculated from the first 8 characters via the CUSIP modulo-10 algorithm; allows downstream systems to detect transcription errors before placing trades.
Why 13F filings use CUSIPs, not tickers
A Form 13F must identify every long position with sufficient precision that there is no ambiguity about the security. Tickers don't meet this bar:
- Tickers can be re-used across companies after delisting (e.g., NYSE recycles them)
- Same company can have multiple tickers (Google had GOOG + GOOGL after 2014 split)
- Same security trades under different tickers across exchanges
- Class A vs Class B share tickers can collide with totally unrelated companies
- ADRs vs ordinary shares have different tickers for the same economic claim
The CUSIP resolves all of these. Berkshire Class B is 084670702, period. The SEC accepts no ambiguity in 13F line items; the CUSIP is how that's enforced.
CUSIP vs ISIN — the global view
For U.S. and Canadian securities, the CUSIP is the national identifier. Internationally, the equivalent is the ISIN (International Securities Identification Number), a 12-character identifier defined by ISO 6166. For U.S. securities, the ISIN embeds the CUSIP: US-037833100-7 — country code (US) + 9-character CUSIP + 1 ISIN check digit. Every U.S. listed security thus has both a CUSIP and an ISIN that encodes the same CUSIP — the ISIN is just CUSIP + country + check digit.
The licensing catch
The CUSIP database itself is commercially licensed, operated by CUSIP Global Services (a joint venture between Standard & Poor's and the American Bankers Association). Bulk access requires a fee. The SEC, however, publishes every 13F filing with CUSIPs free of charge via EDGAR; the CUSIPs that appear on individual filings are public information. The friction is in the master cross-reference (CUSIP ↔ issuer name) at scale, which downstream tools (HoldLens included) maintain via SEC + supplementary sources.
Our view
CUSIPs are the unglamorous infrastructure of public-markets research. Every 13F line, every Form 4 transaction, every bond trade, every clearing instruction — they all reduce to a CUSIP. Retail investors rarely see them; professionals never look at anything else.
On HoldLens, the CUSIP is invisible to the reader by design — we resolve each 13F CUSIP to the canonical ticker and company name. But the underlying identity is the CUSIP, not the ticker. When you read a HoldLens position, the SEC accession number + CUSIP combination is the citation-grade proof of what we're showing you.
Pure-reference encyclopedic entry for Form 13F (where CUSIPs are reported) on our sister site: secfilingdex.com/learn/13f — SEC regulatory citation + every 13F variant.
Foundational reading on securities analysis
CUSIPs are the plumbing; these books are the architecture. Graham, Lynch, Munger — the foundations.
Bookshop.org affiliate links — HoldLens earns a 10% commission if you buy, at no extra cost to you. Bookshop.org is the indie-bookseller consortium that supports local bookstores. These are the books we actually recommend. Always do your own research.
Not investment advice. See methodology for how we parse CUSIPs from every 13F filing.
Cite this page
Researchers, journalists, and Wikipedia editors — citation formats load with the page. HoldLens content is freely available for reference; please cite.
See CUSIP-tagged 13F holdings on HoldLens
Every live position on HoldLens is keyed to the SEC's reported CUSIP, with cross-references to ticker and issuer for human-readable navigation. Sister property cataloging every form type: SecFilingDex.