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Market Cap

Market Cap = Share Price × Shares Outstanding

Market cap is the total dollar value of a company’s stock. It is share price times how many shares exist — not the price you see on a quote.

01 Feel it first

Pick a company size

Tap a size card — Micro, Small, Mid, Large, or Mega — and watch price × shares turn into one big number. That number is market cap.

$100
$1$500
1.5B
0.1B20B
Company size (area scales with market cap)
Price and share count are independent levers. Either one can move size without the other.
Market Cap
$150.0B
$100 × 1.5B shares · Large

At $100 a share with 1.5B shares outstanding, the company is worth $150.0B. That is Large. Large-cap. Broad coverage, liquid, the core of most indexes.

02 Break the intuition

A $5 stock can be a bigger company than a $300 one

Share price alone does not tell you size. Guess which company is larger, then reveal how many shares each one has.

COMPANY A
$300
per share
Shares outstanding100M
Price × shares300 × 100M
$30B
Smaller
COMPANY B
$5
per share
Shares outstanding10B
Price × shares5 × 10B
$50B
Larger
Company B is larger — $50B vs $30B — even though its shares cost $5. Share price is just the size of one slice. Market cap is the whole pie.

03 Build the number

Price times shares

Toggle each chip. Price times shares is market cap. Double the share count and the pie grows while the sticker price stays put.

$20M × $500M = $10B
Market cap
$10B

Price × shares is market cap. At $20 and 500M shares that is $10B. Toggle double the shares: the sticker price stays $20 but the company size doubles.

04 Sort it

Size is not share price

Each card shows price × shares. Sort by how big the whole company is, not how the share looks.

Sort each firm by size. Ignore the share price.

0 / 4 correct

Tap a card, then tap a bucket.

05 Two flavors

All shares vs shares that trade

Same company, two ways to count. Outstanding means every share that exists. Float means only the ones that trade freely.

Shares outstanding means every share the company has issued — including ones held by founders, employees, and big partners. Market cap uses this count: price × shares outstanding.

06 The catch

Investors talk in size buckets

People group companies as micro, small, mid, large, or mega. The cutoffs are habits, not laws — but funds and indexes use them.

Mega $200B+
Mega
Large $10–200B
Large
Mid $2–10B
Mid
Small $300M–2B
Small
Micro <$300M
Micro

Common size labels. Live market-cap screens available on Amsflow.

07 Check yourself

Five quick checks

Question 1 of 5
Quick checkA stock trades at $10 with 2B shares outstanding. Its market cap is:
$20B is right. Market cap = price × shares = 10 × 2B = $20B.

08 Where it breaks

When market cap misleads

Index rules can jump overnight

A company can sit just under an index cutoff for years, then get added in a rebalance. The business did not suddenly grow that day — the list did.

Two classes of shares confuse the count

Some companies have voting and non-voting shares. Market cap usually adds them up, but who controls the company and what freely trades can look different.

Foreign receipts are not always 1-for-1

An ADR (a U.S. receipt for a foreign stock) may stand for a fraction or a bundle of home-market shares. Multiply the wrong count and you invent a fake size.

It ignores cash and debt

Market cap is equity only. A company with lots of debt can look “smaller” on market cap while the whole business would cost much more to buy.

Look up a real market cap.

Open any of 70,000 stocks and see live market cap next to price and share count. Then screen the whole market by size in one click.