What is a CIK? SEC Central Index Key
A CIK, short for Central Index Key, is the unique number the US Securities and Exchange Commission (SEC) assigns to every filer in its EDGAR system. Companies, funds, and individuals such as corporate insiders each get one when they first register to file. A CIK is the reliable way to pull together everything a single entity has ever filed, because unlike a name or ticker it never changes and is never reused. This guide explains what a CIK is and why it matters for reading filings. It is not investment advice.
Definition
A CIK (Central Index Key)
is the unique number the SEC assigns to every EDGAR filer: public companies, funds, and individuals like corporate insiders. It is permanent, is not reused, and does not expire, so it reliably links all of an entity's SEC filings. Source: SEC.
Why does the CIK matter?
Names and tickers are slippery. Companies rebrand, tickers get reassigned, and two different entities can share a similar name. A CIK does none of that. Because the SEC ties every filing to the filer's CIK, it is the anchor that groups a company's 10-K annual reports, its insiders' Form 4 trades, and every other submission under one identifier you can trust.
Permanent and unique
A CIK is not reused and does not expire, unlike a name or ticker
Source: SEC
How is a CIK different from a CUSIP or an ISIN?
A CIK identifies a filer; a CUSIP or an ISIN identifies a security. One company has a single CIK but can have many securities, each with its own CUSIP or ISIN. A LEI is a third kind of code that identifies a legal entity globally. When you read a 13F, holdings are listed by CUSIP; when you look up who filed it, that filer is keyed by CIK.
How to find a CIK
Use the SEC's CIK lookup or the full-text search on EDGAR and type the company or fund name. Once you have the CIK, you can search EDGAR for every filing that entity has made, in order, from one place.
Where the CIK fits when reading filings
For anyone tracking institutional ownership or a fund's 13F across quarters, the CIK is what keeps a manager's filings tied together even if the fund renames itself. It is the plumbing behind a clean filing history.
Flock reads disclosure filings and keeps each one dated and linked back to its source, so you can move from a summary to the original EDGAR record in one step. What any of it means for your money is your call to make.
Frequently asked questions
What is a CIK number?
A CIK, or Central Index Key, is the unique number the SEC assigns to every filer in its EDGAR system, including public companies, funds, and individuals such as corporate insiders. It is the canonical identifier for all of that filer's SEC filings. Source: SEC.
How many digits is a CIK?
A CIK is a numeric identifier commonly shown as up to 10 digits, often padded with leading zeros. It is assigned when a filer first registers to file on EDGAR. Source: SEC.
Does a CIK ever change?
No. A CIK is permanent. It is not reused for another filer and it does not expire, which makes it more reliable than a company name or ticker symbol, both of which can change or be shared over time. Source: SEC.
How do I find a company's CIK?
Use the SEC's CIK lookup or full-text search on EDGAR and enter the company or fund name. The results show the CIK, which you can then use to pull every filing that entity has made. Source: SEC EDGAR.
Flock tracks these filings, sourced, dated, and linked back to the original. See what smart-money entities disclosed, without the guesswork about what it means.
Disclosures shown are public regulatory filings. Data may be delayed or incomplete. Smart-money entities may no longer hold positions shown. Not investment advice.