Regulators publish weekly breakdowns of futures open interest by participant category, separating commercial hedgers from managed money and other reportable groups. It is the only regular public read on whether a move came from fresh buying, from longs closing out, or from hedgers adjusting cover.
The categories are the useful part and also the limitation. A position is classified by the entity that holds it, not by its purpose, so a physical trader running a speculative book sits in the commercial category and a fund hedging a structured product sits in managed money. The classification is administratively consistent and economically approximate.
Two limitations matter and both are structural rather than fixable. The data is a Tuesday snapshot published Friday, so it is stale on arrival by three days that frequently include the most interesting price action of the week. And it counts contracts, not conviction: a position of a given size tells you nothing about the holder's pain threshold or their remaining capacity.
The reported figures also cover only exchange-traded futures and options in the reportable categories. Over-the-counter exposure, physical positions and non-reportable small positions are outside it. So the report is a partial census of one venue, which is a meaningful thing and not a complete picture of market positioning.