Definition. Daily trading volume of US-traded spot ETFs that hold the selected crypto asset as their underlying. One series per ETF ticker.

Interpretation. A measure of liquidity and investor activity in each ETF — higher volume points to stronger participation and easier execution. Available both as the number of ETF shares traded (native) and as the equivalent USD value, so volume can be compared in unit or dollar terms across tickers.

Technical. Daily share volume per ETF symbol from the US equity (OPRA) feed. The USD series is the share volume multiplied by that day's closing price. ETFs trade on weekdays only, so no datapoint is produced on weekends or market holidays.