ShortAtlas methodology
Short volume ratio explained
Short-volume ratio compares reported short volume with reported total volume. Learn what it can show and why it has important limits.
What the ratio compares
Short-volume ratio compares reported short-sale volume with reported total volume in the same source context for a trading day.
The denominator is not always full consolidated market-wide volume. That is why ShortAtlas labels the metric as reported total volume and shows source limitations.
Why high short volume can be misunderstood
A high short-volume ratio does not automatically mean investors are building large bearish positions. Daily short-volume activity can include market making, hedging, intraday activity, and covering.
Daily short volume is trade-flow data. It should not be read as the same thing as Short Interest, which is a reported open-position balance.
How ShortAtlas presents it
ShortAtlas shows short volume, reported total volume, short exempt volume where available, and the calculated percentage for the latest generated trading day.
The page also shows as-of and generated-at timestamps so users can see when the data was sourced and when the site was updated.
Why the ratio is often near half
Short-volume ratios in the 40 to 60 percent range are common across many liquid symbols on many trading days. This surprises users who expect a high reading to be rare or notable.
The main reason is market making. When a liquidity provider fills a customer buy order without holding the shares, the resulting sale is marked short even though the firm intends to flatten the position quickly. That mechanical activity sits inside the same numerator as directional short selling.
Short exempt volume
Some short sales are flagged as short exempt, meaning they were executed under an exception to the price test in Regulation SHO. ShortAtlas reports this field separately when the source file provides it.
Short exempt volume is a subset of reported short activity and is shown for completeness. A larger or smaller value does not by itself indicate anything about a company or its share price.