The proposition was tantalizing: Handsome returns awaited investors who would be willing to provide an infusion of cryptocurrency to Elon Musk, the billionaire chief executive of Tesla and founder of SpaceX, for a moneymaking venture.
It seemed too good to be true, because it was.
Investors lost $2 million in six months to fraudsters who impersonated Mr. Musk, the Federal Trade Commission said in a report released on Monday that was meant to draw attention to a spike in cryptocurrency scams.
The commission found that nearly 7,000 people lost a reported $80 million over all from October through March as part of various scams targeting investors in Bitcoin and other cryptocurrencies like Dogecoin, a nebulous marketplace that Mr. Musk has bullishly promoted on Twitter. The median amount that they lost was $1,900, according to the commission.
The spate of fraud cases — a nearly 1,000 percent increase compared with the same period the previous year, the…