Two different things live on this page, and mixing them up is the whole point. Positioning — what speculators actually hold — comes from the CFTC (weekly) and from FINRA short interest (twice monthly). Short-sale volume — the original chart, at the bottom — is a tape statistic and cannot tell you what anyone is positioned for, because most short-marked volume is market makers providing liquidity, not anyone betting against the market.
When a market maker fills your buy order and does not happen to be holding the stock, that sale is legally marked short. It is printed as a short sale even though the market maker is simply providing liquidity and will flatten out minutes later. Liquidity provision, not positioning. The same is true of index-arbitrage, ETF market making and hedging legs.
So a high short-volume share is normal, not bearish. Measured on the data in the chart below:
Over half of all volume being marked short is the ordinary state of a calm market. This series is not a positioning indicator and not a sentiment indicator. The net line below is long volume minus short volume: it is structurally true and directionally meaningless — it moves with how much market-maker inventory happened to be short-marked that day, not with what investors think. To see what speculators actually hold, use panes 1 to 4 above.
Every chart: mouse wheel zooms the dates · drag sideways pans · shift + wheel (or the Y slider) stretches the values · click a chart to pin a copyable readout, click empty space to clear it · the bar under each chart drags its height · Full fills the screen · PNG saves the picture with its labels drawn on. Pills under a chart hide and show lines; Show all / Hide all do every line at once.