Block slides 20% after short-seller Hindenburg says 2-year investigation indicates the company has 'wildly overstated' genuine user counts

• Block shares drop 20% on Thursday after Hindenburg Research said it's shorting the payments company. 
• The famed short-seller said an investigation indicated the company used inflated metrics.
• Hindenburg alleged Block "obfuscates" how many individuals are on its Cash App platform. 

Block plunged Thursday after Hindenburg Research said it's shorting shares in the payments company, alleging it has mislead investors with inflated metrics.

Block, whose CEO is Jack Dorsey, didn't immediately reply to Insider's request for comment about the short-seller's allegations. 

Block shares dropped 19.5% to $58.51 as trading in Thursday's regular session got underway.