Scanners 101

Price filters establish the basic universe of stocks you’re willing to trade.

Last Price is the current trading price - your starting point for almost every scan. Day traders often set bounds like $1-$20 (volatile enough to move, cheap enough to size into). Swing traders might prefer $5-$200 for better liquidity and tighter spreads.

Open, High, Low, Close capture session price points. Comparing Last to these values reveals where price sits in its daily range. A stock trading near its High suggests strength; near its Low suggests weakness or potential bounce.

Bid and Ask show current quote prices. The spread between them (available as both dollar Spread and percentage % Spread) indicates liquidity - tight spreads under 0.5% mean you can enter and exit without excessive slippage.

% On Bid and % On Ask reveal order flow. High % On Bid means most trades are executing at the bid (selling pressure). High % On Ask means buyers are lifting offers (buying pressure). These filters help gauge the conviction behind price movement.

Range and % Range measure the High minus Low for the session - a volatility indicator. Higher range stocks offer more trading opportunity but also more risk.

Change filters find stocks that are moving - the heart of momentum scanning.

Percent Change measures the move from previous close. This is your primary momentum filter. Gapper scans typically look for 5-10%+ pre-market change. Intraday momentum scans might use 2-5%+ regular hours change.

Gap specifically measures the opening price versus previous close - the overnight move before any trading occurs. Different from Percent Change, which continues updating throughout the day.

Net Change shows the dollar move rather than percentage - useful when you care about absolute moves regardless of stock price.

Change from Open (both $ and %) measures intraday progress since the session started. A stock might be up 3% from yesterday’s close but down 2% from today’s open - these filters let you distinguish those situations.

Change from High and Change from Low reveal pullback depth or bounce strength. A stock up 10% but currently 5% off its high has pulled back significantly. These filters help time entries during trends.

Volume is the fuel behind price movement. Without volume, moves lack conviction and are more likely to reverse.

Volume counts shares traded during the selected session. Day traders typically require 500K+ for adequate liquidity. Swing traders can work with less but should still ensure enough volume to enter and exit positions cleanly.

Dollar Volume (Volume times Price) provides a truer liquidity measure. A $1 stock trading 1M shares represents $1M of liquidity. A $100 stock trading 100K shares represents $10M. Dollar volume normalizes this.

Trades counts the number of transactions - distinct from volume, which counts shares. High trade count indicates sustained interest from multiple participants rather than a few large block trades.

Relative Volume (RVOL) compares current session volume to the stock’s historical average daily volume. This is arguably the Scanner’s most important filter for finding unusual activity. RVOL of 2 means the stock is trading at twice its normal daily pace - something is happening. RVOL of 5+ indicates extreme interest. Note that RVOL compares to the overall historical average, not to the same time of day on previous days - so it won’t tell you if 9:30 AM volume today is higher than 9:30 AM volume yesterday.

Float Rotation shows what percentage of the tradeable float has changed hands. Above 50% indicates high interest. Above 100% means the entire float has traded at least once today - extreme situations where supply/demand dynamics are most pronounced.

Technical filters let you scan for specific chart conditions across thousands of stocks.

VWAP (Volume Weighted Average Price) is the benchmark price institutions use. Day traders commonly filter for stocks trading above VWAP (bullish) or watch for VWAP reclaims after pullbacks.

RSI (Relative Strength Index, 14-period) measures momentum on a 0-100 scale. Below 30 suggests oversold conditions; above 70 suggests overbought. Contrarian traders scan for extremes.

Moving Averages (SMA and EMA for 9, 20, 50, 200 periods) identify trend direction. Comparing Last Price to these averages reveals whether a stock is above or below key support/resistance levels. Scanning for price crossing above the 20 SMA, for example, catches potential trend changes.

MACD and MACD Signal measure momentum divergence. Positive MACD suggests upward momentum; crossovers generate entry signals.

Bollinger Bands (Upper and Lower) define volatility-based channels. Stocks trading outside the bands are statistically extended and may revert.

ATR (Average True Range) quantifies typical daily movement. Useful for position sizing and setting stop losses appropriate to each stock’s volatility.

These filters help you understand what you’re trading.

Float is the number of shares available for public trading - total shares minus insider and institutional holdings that rarely trade. Float is critical for understanding volatility potential. A $10 stock with 5M float can move 50% in a day on modest volume. The same $10 stock with 500M float rarely moves more than 5%.

Low float stocks (under 10-20M shares) are volatile. They move fast when volume arrives because there’s limited supply to absorb buying pressure. This cuts both ways - they can squeeze higher quickly but also dump just as fast.

Shares Outstanding is the total shares issued. Useful for context but less actionable than float for trading purposes.

Market Cap shows the total market value (price times shares outstanding). Useful for filtering by company size: micro-cap under $300M, small-cap under $2B, mid-cap under $10B.

Short interest data reveals potential squeeze setups.

Short Float % shows what percentage of the float is currently sold short. Above 20% is considered heavily shorted. When heavily shorted stocks spike on volume, short sellers rushing to cover can accelerate the move - the famous “short squeeze.”

Short Ratio (also called “days to cover”) divides short interest by average daily volume. A ratio above 5 means it would take shorts 5+ days to cover at normal volume - they’re trapped if the stock runs.

Short Interest provides the absolute number of shares sold short, useful for context alongside the percentage metrics.

While the Scanner excels at technical and momentum scanning, fundamental filters let you overlay basic quality criteria.

Revenue and EPS (Earnings Per Share) filter by actual business metrics. Some traders want profitable companies only; others specifically seek beaten-down stocks with poor fundamentals for potential turnaround plays.

P/E Ratio, P/S Ratio, and P/B Ratio provide valuation context. Low P/E might indicate value; high P/E might indicate growth expectations or overvaluation depending on your perspective.

News Count shows how many headlines a stock has today. Filtering for stocks with recent news helps focus on names with catalysts driving their moves.

Last News indicates how recently news hit. A stock moving on news from this morning is different from one moving on news from last week.