Indicator with aggregated volume for all the most actively traded bitcoin perpetual swaps.
Can be denominated in either US dollars or the number of coins traded.
Can be displayed as stacked volume or an index that shows the percentage market share each contract has.
In the settings you can exclude any contract so that it only shows the individual and total volume of the markets you're interested in.
"Linear" or "inverse" refers to the type of perpetual swap contract it is.
Inverse contracts use coin margin, so in this case BTC.
Linear contracts use some type of dollar equivalent margin like USDT for example.
The margin is always specified for the linear contracts.
It's public and free for anyone to use.