Market cap is now close to ~$11B, for a company that over the last 12 months burned ~$240M in cash. Revenues declined by ~11%. Net cash on hand is ~$600M. It's hard to justify purchasing the shares at the current price based on the company's recent results. Its future prospects don't seem particularly promising either.

A stock's price is set by the marginal buyer and seller. For example, a single share that trades at 50% less than the last price instantly brings market cap down by 50%. Once all the retail investors loading up on the stock have purchased as much as they can hold, very little marginal trading volume can bring the stock price back down.