Investors sort companies into size buckets by market capitalization, from mega-cap at the top down to micro-cap at the bottom. The tiers are a shorthand for how large a company is. The thresholds are conventions rather than rules, so sources draw the lines a little differently, but the ranges below are the ones you will see most.
Key takeaways
| Tier | Typical market cap | Rough feel |
|---|---|---|
| Mega-cap | $200 billion or more | Household names at the top of the ranking |
| Large-cap | $10 billion up to $200 billion | Big index members, still very liquid |
| Mid-cap | $2 billion up to $10 billion | Between large and small by size |
| Small-cap | $300 million up to $2 billion | Smaller; often thinner trading |
| Micro-cap | Below $300 million | Thinly traded; many sit below our ranking floor |
Each lower bound is included. The next tier starts at the upper figure, so a company at exactly $200 billion is mega-cap on this page, not large-cap. Other data vendors draw these lines in different places. This ranking only includes names at about $1 billion or more, so conventional micro-caps — and much of small-cap — never appear here.
This article does not freeze live market-cap quotes. Open Apple or NVIDIA for the as-of figure that decides whether that name still sits in mega-cap that day. The $200 billion line above is the convention on this page, not a snapshot of those companies.
Because market cap tracks the share price, companies drift between tiers over time. A fast-growing mid-cap can graduate to large-cap, and a struggling large-cap can slide down.
They are a fast filter: mega vs small is a size comparison you can do without reading a 10-K. Liquidity tends to scale with size, which is why funds and indexes are often built around a single band.
The cutoffs vary by source. A name can sit in large-cap on one site and mega-cap on another. The labels say nothing about profits, debt, or whether the stock is “better.” A mega-cap is not automatically a better investment than a small-cap; it is simply bigger.
Size tiers turn up everywhere in investing. Many funds and indexes are built around a single tier. Filtering by tier is a fast way to narrow thousands of companies down to the ones you want to inspect.
To see where any company sits today, browse the full ranking or drill into a sector. For how industry groups work, see What Is a Sector?.
For general education only. Nothing here is investment advice.
Formulas and worked examples are MarketCapLens's. See who checks the numbers.