Shares in the US payment service block fell more than 20 percent in early US trading on Thursday. Research firm Hindenburg Short published a previous report accusing Twitter co-founder Jack Dorsey’s company of misleading investors with inflated metrics.

Among other things, the real user numbers are much lower. Block – formerly known as Squire – has not yet responded to Hindenburg’s allegations.

Activist short sellers like the Hindenburg make money by betting on falling share prices and then publishing a report blaming the company. In 2020, the Hindenburg caused shares of electric car maker Nikola to plummet, and in January, it caused a sale of shares in businessman Gautam Adani.

more: American activist money is increasing the pressure again