Elon Musk, already the chairman of rooftop solar installer SolarCity and its biggest shareholder, bought $5 million more of the company’s stock on Monday.

SolarCity logoFounder, chairman, and major shareholder — as well as the CEO of both Tesla and SpaceX — Elon Musk made use of Monday’s horrible stock market trends to pick up 123,510 shares in SolarCity at $40.49 — a low that has not been surpassed since October, 2013. This purchase, though impressive, only boosts Musk’s holdings in SolarCity by about 0.6%.

Bloomberg Business pointed out that “Musk expanded his position after hedge fund manager Jim Chanos said Friday that he’s short on the company,” which triggered a “rout that drove the shares down 13%.”

SolarCity announced its second quarter earnings late July, and though the company suffered a net loss of $22.4 million, it nevertheless saw record installations and bookings.

GTM Research places SolarCity as the largest rooftop solar developer in the US by far — with 34% of installations, well above its nearest competitors — Vivint Solar has 12%, and Sunrun 10%.