What Is Float in Stocks? Low Float vs High Float Explained
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If you’ve ever looked at a stock scanner and seen a column labelled float, you might have wondered exactly what it means and why so many traders pay close attention to it. Float is one of the most important — and most overlooked — concepts in active trading. Understanding it can completely change how you read a stock’s potential for big moves.
This guide explains what float means, the difference between low float and high float stocks, and how to use float as part of your scanning routine.
What Is Float in Stocks?
Stock float refers to the number of shares of a company that are actually available for the public to trade. It is a subset of the total shares a company has issued.
Here is the key distinction:
- Shares outstanding — the total number of shares a company has issued, including those held by insiders, executives and institutional investors who are restricted from selling.
- Float — only the shares that are freely tradable on the open market, after removing restricted and closely held shares.
For example, a company might have 50 million shares outstanding, but if 20 million of those are held by insiders with lock-up agreements, the float is only 30 million shares. Those 30 million shares are what the market is actually trading.
How Float Is Calculated
The basic formula is straightforward:
Float = Shares Outstanding minus Restricted Shares minus Insider Holdings minus Locked-Up Shares
Restricted shares are those that cannot be sold due to regulatory restrictions, employee lock-up periods after an IPO, or other contractual agreements. Once restrictions expire, shares can enter the float and increase its size.
Low Float Stocks vs High Float Stocks
This is where float becomes practically useful for traders. The size of a company’s float has a direct impact on how volatile and liquid a stock is.
What Is a Low Float Stock?
A low float stock has a small number of shares available for trading — typically under 20 million shares, though many traders focus on stocks with floats under 10 million. Because supply is limited, even modest buying pressure can push the price up sharply.
Characteristics of low float stocks:
- High volatility — prices can move 20%, 50% or more in a single session
- Wide bid-ask spreads — less liquidity means larger gaps between buyers and sellers
- Susceptible to news catalysts — a press release or earnings beat can trigger explosive moves
- Popular with momentum and day traders looking for rapid price action
- Higher risk — moves can reverse just as fast as they happen
Low float stocks are a staple of momentum trading strategies. When a low float stock gets a positive catalyst — such as a clinical trial result, a contract win or a surprise earnings beat — the limited supply of shares means demand can quickly outstrip supply, sending the price surging.
What Is a High Float Stock?
High float stocks have hundreds of millions or even billions of shares available for trading. This is typical of large-cap companies like Apple, Microsoft or Nvidia.
Characteristics of high float stocks:
- Lower volatility — large supply absorbs buying and selling pressure more smoothly
- Tight bid-ask spreads — high liquidity makes it easy to enter and exit positions
- Slower, more predictable price movements
- More suitable for swing traders and investors focused on fundamentals
- Lower risk of sharp reversals caused by thin order books
High float stocks are harder to move significantly on a percentage basis, which is why they tend to suit traders who prefer lower volatility and tighter risk management.
Why Float Matters for Stock Scanners
Float is one of the most commonly used filters in professional stock scanners. When you scan for momentum stocks — particularly pre-market movers or gap-ups — filtering by float helps you focus on the stocks most likely to make large percentage moves.
A stock with a float of 5 million shares that reports strong earnings might gap up 30% at the open. The same news in a stock with 500 million shares might barely move the needle. Supply and demand dynamics are simply different.
If you use a scanner like Trade Ideas or Finviz, you can filter stocks by float size to target either high-momentum low float plays or more stable high float setups, depending on your strategy.
Float and Relative Volume: A Powerful Combination
Float works especially well when paired with relative volume (RVOL). If a low float stock suddenly trades at five times its average daily volume, that combination — low supply plus abnormal demand — is exactly the kind of setup momentum traders look for.
Relative volume tells you how much interest there is. Float tells you how much supply there is to absorb it. Together they give you a clearer picture of whether a move has real momentum behind it.
What Is Short Float?
You may also encounter the term short float, sometimes called short interest as a percentage of float. This measures how many of the available shares are currently being sold short.
A high short float percentage — typically above 20% — means a significant portion of available shares are held by short sellers betting the price will fall. If the stock instead rises, those short sellers may be forced to buy to cover their positions, which can create a short squeeze — an additional surge in buying pressure on top of whatever catalyst triggered the original move.
Short float is an important secondary metric when evaluating low float momentum plays. A high short float combined with a positive catalyst can amplify a move significantly.
Float vs Shares Outstanding: Key Differences
| Metric | What It Measures | Includes Restricted Shares? |
|---|---|---|
| Shares Outstanding | All issued shares | Yes |
| Float | Freely tradable shares only | No |
| Short Float | Shares sold short as % of float | No |
How to Find Float Data
Most modern stock scanners and screeners display float as a standard data point. Here is where you can find it:
- Trade Ideas — includes float as a built-in filter in its real-time scanner, ideal for intraday momentum strategies
- Finviz — lets you filter by float in the screener under the Shares filters
- TradingView — float is available as a screener filter and shown on individual stock pages
- Benzinga Pro — displays float in the signals and news feed context for pre-market movers
Float Categories at a Glance
| Float Size | Classification | Typical Behaviour |
|---|---|---|
| Under 10M shares | Very Low Float | Highly volatile, large percentage moves possible |
| 10M to 50M shares | Low Float | Good momentum potential with the right catalyst |
| 50M to 200M shares | Mid Float | Moderate volatility, more predictable |
| 200M+ shares | High Float | Lower volatility, easier to trade in size |
Summary
Float is the number of shares freely available for the public to trade. It differs from shares outstanding because it excludes restricted and insider-held shares.
Low float stocks have limited share supply, which makes them highly reactive to news and volume spikes — and a core focus for momentum and day traders. High float stocks are more stable and predictable, suiting swing traders and investors with longer time horizons.
When used alongside filters like relative volume and price change, float becomes one of the most powerful tools in a stock scanner setup. Whether you are looking for the next explosive pre-market mover or a steady breakout candidate, knowing the float gives you a critical edge in reading how a stock is likely to behave.
If you want to start scanning for low float stocks, take a look at our guide to the best stock scanners for active traders, or explore our full library of trading education guides.