MicroStrategy’s (MSTR) big bet on Bitcoin (BTC) has been a wild ride, sending their stock up over 2,500% in five years. But now, one analyst thinks the good times might be coming to an end.

Analyst Gus Gala from Monness Crespi recently changed his tune on MicroStrategy. ‘Even though we had some initial concerns,’ he wrote, ‘it’s becoming clearer that their strategy of issuing convertible securities to buy more Bitcoin is probably running out of steam.’ Gala downgraded MSTR to ‘sell’ just two weeks after initially rating it ‘neutral’.

MicroStrategy isn’t slowing down on its Bitcoin accumulation. They currently hold a massive 528,185 BTC and have been snapping up large amounts almost weekly in recent months. They’ve been funding these purchases mainly by issuing common shares and selling off their first preferred stock series, STRK.

Gala’s price target is $220, which means he sees the stock price falling nearly 30% from its current level around $300.

Gala’s main point is that it’s going to get harder and harder for MicroStrategy to keep raising money by issuing shares to buy more Bitcoin. This may force them to rely more on fixed income options instead.

He adds, ‘Unless they start issuing more fixed income securities, their whole Bitcoin investment strategy could face some serious headwinds.’

Gala also pointed out that MicroStrategy has already tapped into a whopping $18.6 billion of its $21 billion share offering program. And just last week, they raised another $711 million through STRF, their second preferred stock offering.