Take copper for example. Suppose the value of the primary contract is 20W and the margin ratio is 5%, which means that you can buy 20W copper with 5% of 20W, that is,1w. Isn't that 20 times?

Suppose a fund holds 200 million shares of assets, then it can sell up to 400 million stock indexes. Now a stock index contract is almost 80W, so it is 500 lots, and at most 500 stock index futures can be sold!