Relative Volume (RVOL)

Relative volume is calculated by dividing the current volume by the average volume for the same time period:

RVOL = Current Volume / Average Volume (same time of day, same lookback period)

The time-of-day adjustment is critical. Stocks naturally trade heavy volume at the open (9:30-10:00 AM ET), light volume midday (12:00-2:00 PM), and heavier volume near the close (3:00-4:00 PM). Without this adjustment, every stock would look like it has high volume at the open and low volume at lunch.

A proper RVOL calculation uses the average volume at the same 5-minute or 15-minute interval over the past 10-20 trading days. For example, if a stock averages 50,000 shares between 10:00-10:05 AM over the last 20 days, and today it traded 200,000 shares in that same interval, the RVOL at 10:05 AM is 4.0x.

Most screeners simplify this by comparing total volume so far today against the average total volume at this time of day. This is less precise but easier to compute and still effective for filtering.

Common RVOL thresholds for day trading:

• Below 0.5x: Dead stock, avoid for intraday
• 0.5x - 1.0x: Normal activity, no unusual interest
• 1.0x - 1.5x: Slightly above normal, worth monitoring
• 1.5x - 3.0x: Elevated activity, good day trading candidate
• 3.0x - 5.0x: Significant unusual volume, high-priority candidate
• Above 5.0x: Extreme volume, often catalyst-driven, highest conviction

Absolute volume (total shares traded) is misleading because it varies enormously between stocks. AAPL trades 60 million shares on a normal day. A small-cap biotech might trade 200,000 shares. Comparing their raw volumes tells you nothing about which one is experiencing unusual activity today.

RVOL normalizes for this difference. If AAPL is trading at 1.2x RVOL, it is slightly busier than usual but nothing special. If the small-cap biotech is at 8.0x RVOL, something significant is happening even though its absolute volume is tiny compared to AAPL.

High RVOL stocks are better day trading candidates because: (1) Liquidity is elevated, so you can enter and exit with less slippage. (2) Spreads tighten when more participants are trading. (3) Price movement is more likely to follow through because the increased participation creates momentum. (4) The underlying catalyst driving the volume gives directional conviction.

Low RVOL stocks are dangerous for day trading because: price movement is choppy without follow-through, spreads widen, limit orders may not fill, and you risk becoming the largest participant in the stock — moving the price against yourself.

RVOL is one of the most effective screening filters because it eliminates 80%+ of the stock universe in a single step. Here is how professional day traders use RVOL in their screening workflow:

Pre-market scan (7:00-9:30 AM ET): Filter for stocks with pre-market volume above 2x their average pre-market volume. This identifies stocks with overnight catalysts (earnings, upgrades, news, biotech events). Pre-market RVOL is the earliest signal that a stock will be in play at the open.

Opening scan (9:30-10:00 AM): Combine RVOL above 2.0x with a minimum price filter ($5+) and gap percentage (gapping up or down 2%+). This gives you the shortlist of stocks most likely to produce clean intraday trends.

Midday filter (11:00 AM-2:00 PM): Raise the RVOL threshold to 3.0x+ for midday trades. Volume naturally drops midday, so a stock maintaining high RVOL during the lull indicates sustained institutional interest rather than just opening frenzy.

Combine RVOL with other filters for highest quality setups:

• RVOL 2.0x+ AND ATR% above 3% = volatile + liquid
• RVOL 3.0x+ AND gap above 4% = catalyst-driven momentum
• RVOL 2.0x+ AND near 52-week high = breakout candidate
• RVOL 5.0x+ AND float under 20M shares = potential short squeeze candidate

Not all high-RVOL stocks are good trades. Watch for these common traps:

Earnings day inflation: On earnings day, almost every stock has elevated RVOL. The post-earnings gap and initial reaction often happen too fast for retail traders to capture. Wait for the RVOL to remain elevated 30+ minutes after the open before trading earnings movers.

Halted stocks: Stocks halted for circuit breakers or news will accumulate pending orders that flood in when the halt lifts, creating artificial RVOL spikes. The first few minutes after a halt resumption are extremely volatile and spread-heavy.

Low-float manipulation: Micro-cap stocks with very low float (under 5M shares) can have extreme RVOL from relatively small dollar volume. A $50,000 order in a stock that normally trades $10,000 per interval creates 5.0x RVOL but represents no institutional interest. Filter out stocks under $5 and with average daily dollar volume under $5M.

End-of-day rebalancing: Index rebalancing, ETF creation/redemption, and portfolio rebalancing cause RVOL spikes in the last 15-30 minutes of trading. This volume is non-directional and does not signal conviction.

RVOL decay: A stock that opens at 8.0x RVOL may drop to 1.5x RVOL by midday. The volume spike was front-loaded and the stock has lost its momentum. Track RVOL over time, not just at a single point.