That is entirely dependent on your idea of "benefit" to society. Accurate pricing of futures means farmers benefit from a price that accurately reflects the sup

That is entirely dependent on your idea of "benefit" to society. Accurate pricing of futures means farmers benefit from a price that accurately reflects the supply and demand of their product. Strong liquidity means farmers can sell large volumes of product without much price slippage. If you take the time to understand what these traders do you'll understand that trading is not parasitic but actually generates value for both sides. What IS parasitic is hedge fund managers that charge fees but deliver subpar investment performance compared to index funds. You refer to the oil futures issue last year as being negative for society but I argue it was actually positive for the productive members of society: because traders bought oil futures, the oil producers themselves were able to get guaranteed buyers for their oil even though there was very little demand. In effect the traders subsidized the uncertainty of pandemic ups and downs and the producers profited off the traders' loss. This is an example of futures working well because that oil otherwise would've been dumped or burned since the price was negative (just like wind farms stop operating when the price is negative or oil drillers burning natural gas because it's too expensive to transport). Without futures farmers would have to buy price insurance through some sort of middleman insurance company, which is almost certainly more expensive than the market.