A rogue trader dealing in wheat future contracts has caused his company more than $140m (£70m) in losses.
The rogue wheat trades come amid soaring wheat prices
Trading giant, MF Global, said it detected unusual trades at one of its US offices on Wednesday.
It found that an employee had been taking large, unauthorised bets on the direction of wheat prices, which cost the company $141.5m to reverse.
MF Global sacked the trader and said that systems designed to stop such unauthorised trading had failed.
MF Global shares plunged on the New York Stock Exchange.
The losses come amid volatile conditions in the wheat market, with wheat prices reaching record highs earlier in the week.
Prices have more than doubled over the past year as the world's farmers have struggled to meet demand.
MF Global's announcement comes after last month's huge losses at Societe Generale.
It blamed trader, Jerome Kerviel, for the $7.4bn in loss.