The farm has wheat, corn and other crops.

“This is the end of the road for my farm,” said Mr. Kono, 60, who grows rice, wheat, red beans and cabbage on 17 acres of farmland here in Iwamizawa, on Hokkaido, Japan’s northernmost main island.

Instead, when a company or an investor wants to buy a derivative contract for, say, oil or wheat or securitized mortgages, an order is placed with a trader at a bank.