Bitcoin ETF outflows do not tell the whole trading story. Net flows, trading volume and assets under management measure different things. Reading one as another can turn a useful observation into a misleading market conclusion. Our guide explains how ETF creations and redemptions work, why cash and in-kind redemptions differ, and how fund assets can rise even during net outflows. It includes a comparison table and hypothetical examples for reading daily and weekly data, with practical checks for reporting windows, missing observations and source differences. The focus is on what the numbers establish, which questions require more evidence, and how to avoid treating every flow as a price forecast.