US stocks took a pounding on Thursday, with the benchmark S&P 500 index turning negative for the year as investors reacted to data showing many more people lost their jobs in June than expected.

Analysts had far underestimated the number of new non-farm employees who would lose their jobs during the month, and even though the unemployment rate and the number of people claiming jobless benefits on a weekly basis were both better than expected, the market sold off heavily.