What is Free Float? Definition, Formula, and Example
Free float is the number of a company's shares actually available for public trading, calculated by subtracting restricted and insider-held shares from total shares outstanding.
What is Free Float?
Free float is the portion of a company's outstanding shares that is genuinely available for trading on the open market. It excludes shares locked up by insiders, founders, executives, strategic corporate holders, governments, and restricted stock that cannot be sold without filing or vesting. When a trader says a stock has a "low float," they mean the tradable supply is small relative to demand — which is why low-float names move violently on modest volume. Free float is the denominator behind liquidity, index weighting, and short-squeeze dynamics, and it is one of the first numbers a serious trader checks before sizing a position.
How Free Float is Calculated
The formula is direct:
Free Float = Shares Outstanding − Restricted Shares − Closely Held Shares
Data providers and index providers apply slightly different rules. S&P Dow Jones and MSCI compute an Investable Weight Factor (IWF) that excludes any holder above roughly 5% who is deemed strategic, plus insider stakes. A simple worked example of the calculation:
- Shares outstanding: 1,000,000,000
- Founder/insider holdings: 200,000,000
- Government stake: 50,000,000
- Free float: 750,000,000 (75%)
Float percentage = Free Float ÷ Shares Outstanding = 75%. Most large caps sit between 70% and 100%. Small caps and recent IPOs frequently trade below 20%.
Worked Example
Take TSLA. With roughly 3.2 billion shares outstanding and Elon Musk holding approximately 13% (about 410 million shares), plus smaller insider stakes, Tesla's free float comes to roughly 2.7 billion shares — a float percentage near 85%. That enormous tradable supply is why Tesla can absorb $20+ billion in daily dollar volume without dislocating.
Contrast that with a low-float small cap trading 8 million shares of float. If 500,000 shares trade in the first hour — over 6% of the entire tradable supply changing hands — price discovery breaks down and the stock can gap 40% on no fundamental news. The 2021 meme-stock squeezes in GME and AMC were amplified precisely because short interest approached or exceeded the effective free float.
When Traders Use Free Float
- Volatility screening: Day traders scan for floats under 20 million shares; these names produce the largest intraday percentage moves.
- Short-squeeze analysis: Squeeze risk is measured as short interest divided by float (float short %), not divided by shares outstanding. A 30% float-short reading on a 10-million-share float is a powder keg.
- Index mechanics: Float-adjusted market cap determines index weights. When a company issues secondary shares or insiders' lock-ups expire, index funds must buy, creating predictable flows.
- Liquidity and slippage estimation: Position size relative to float, not just average daily volume, tells you whether you can exit without moving the market.
Limitations and Common Misconceptions
Free float is not a fixed number. It changes with insider sales, buybacks, secondary offerings, lock-up expirations, and vesting schedules, and data vendors update it on different cadences — two screeners frequently disagree by several percentage points. Second, float says nothing about who holds the tradable shares: a large float concentrated in passive funds trades tighter than the headline number suggests. Third, "low float" is not inherently bullish; it cuts both ways, and low-float names gap down just as fast as they gap up. Finally, float does not equal liquidity — a stock can have a 500-million-share float and still trade 100,000 shares a day.