Key Takeaways
Quick answer
Market cap is the current price of one unit multiplied by the number of units. Investor.gov defines it this way for company shares, and the European Central Bank (ECB) applies the same price-times-supply idea to crypto. It measures size at today’s price, not money invested.
- Market cap is the price of one unit multiplied by the number of units.
- Crypto figures differ depending on whether circulating, total or maximum supply is used.
- A large market cap is not money invested and does not make a coin safe.
How is market cap calculated?
Investor.gov, the SEC’s education site, puts it like this: market capitalisation is “the value of a corporation determined by multiplying the current public market price of one share of the corporation by the number of total outstanding shares.” For crypto, the ECB writes that “the price of a crypto-asset has to be complemented with information on the aggregate supply, which can be measured in several ways.”
Which supply figure goes into the sum?
The ECB lists four: circulating supply, total supply, maximum supply and inflation-adjusted variants that include future issuance. The choice can change the answer a lot.
| Illustrative token at $2 | Units | Market cap |
|---|---|---|
| Circulating supply | 50,000,000 | $100,000,000 |
| Maximum supply | 200,000,000 | $400,000,000 |
Same coin, same price: $2 × 200,000,000 is four times $2 × 50,000,000. Always check which supply a figure uses. Bitcoin’s own maximum is set by the halving schedule.
What can market cap not tell you?
It multiplies the latest price across every unit, even if only a few units changed hands at that price. In a thin market, a small trade can move the whole figure; see liquidity. The ECB also notes that “Without applying any selection criteria, pricing of crypto-assets is very disperse”, meaning prices differ between platforms.
Size is not safety either. The FCA records that Cardano peaked at £2.23 in September 2021 and was £0.29 on 1 December 2025, a fall of 87%. EU supervisors warn that even regulated crypto-assets can be very volatile; see volatility.
Frequently asked questions
Is market cap the money people have put in?
No. Illustrative: if early buyers paid $0.10 and the last trade was $2, a market cap based on 50,000,000 units shows $100,000,000, even though those holders paid only 50,000,000 × $0.10 = $5,000,000.
Does a larger market cap mean a safer coin?
Not on its own. The FCA describes crypto-assets as high risk and speculative as an investment, large or small.
Article Sources
4 sources
Blockhorizon checks every figure, date and quotation against primary sources: regulators, statistics bodies and original technical documents. Read our editorial policy.
- SEC Investor.gov, Market Capitalization (glossary) — investor.gov (accessed 2026-10-02)
- European Central Bank, Understanding the crypto-asset phenomenon, its risks and measurement issues (Economic Bulletin 5/2019) — ecb.europa.eu (accessed 2026-10-02)
- UK Financial Conduct Authority, Crypto: the basics (updated Jan 2026) — fca.org.uk (accessed 2026-10-02)
- EBA, ESMA & EIOPA, Joint ESAs Warning on crypto-assets (2025) — eiopa.europa.eu (accessed 2026-10-02)