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.
Amazon affiliate links — as an Amazon Associate, HoldLens earns from qualifying purchases and membership trials at no extra cost to you. These are books we genuinely recommend. Not investment advice; always do your own research.
New Audible members only · 30-day trial · many of these titles are included with membership.
Not investment advice. See methodology for how we parse CUSIPs from every 13F filing.
Cite this page
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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.