Billionaire Leo Coguane, who calls himself Tesla’s third-largest individual shareholder, has demanded that the company conduct a $15 billion share buyback, CNBC reported.

Responding to a tweet by Tesla’s senior director of investor relations Martin Veach, Coguane said the automaker should buy back $5 billion worth of shares as early as this year and $10 billion next year. It is proposed to use free cash flow to fund the buyback. This, according to the shareholder, should not affect the company’s $18 billion cash reserves.

This is how the billionaire expects to support the stock after its fall.