(Bloomberg) — Syed Shah usually buys and sells stocks and currencies through his Interactive Brokers account, but he couldn’t resist trying his hand at some oil trading on April 20, the day prices plunged below zero for the first time ever. The day trader, working from his house in a Toronto suburb, figured he couldn’t lose as he spent $2,400 snapping up crude at $3.30 a barrel, and then 50 cents. Then came what looked like the deal of a lifetime: buying 212 futures contracts on West Texas Intermediate for an astonishing penny each.
What he didn’t know was oil’s first trip into negative pricing had broken Interactive Brokers Group Inc. Its software couldn’t cope with that pesky minus sign, even though it was always technically possible — though this was an outlandish idea before the pandemic — for the crude market to go upside down. Crude was actually around negative $3.70 a barrel when Shah’s screen had it at 1 cent. Interactive Brokers never displayed a subzero price to him as oil kept diving to end the day at minus $37.63 a barrel.
At midnight, Shah got the devastating news: he owed Interactive Brokers $9 million. He’d started the day with $77,000 in his account.