First of all, I tell you for sure that hundreds of thousands of people upstairs certainly don't understand the leverage system of futures. Here is an example:

Suppose you buy a contract of rapeseed meal 1609, and now the price is 2400 yuan/ton, 10 ton/hand, and the margin ratio is 6%. The first-hand deposit 1440 yuan, 300,000 yuan can buy 208 lots. A 50% increase means an increase of 1200 points, and the profit is1200 *10 * 208 = 2,496,000 yuan.

Secondly, your question is not rigorous. Futures contracts have a time limit, so they cannot be traded at maturity. It usually takes a long time to increase by 50%. A contract usually doesn't have such a big rise and fall from listing to stopping trading, and the issue of changing months is involved in the trading process.