What happened

Hydrogen fuel cell pioneer Plug Power (NASDAQ:PLUG) saw its stock pop as much as 11% in early trading Wednesday before settling down to end the day up 7.6%.

Earnings are the reason, but here's the thing that's going to surprise you: Plug Power hasn't actually reported its earnings yet. Preliminary results are due out tomorrow.

Man riding scooter up an arrow

Investors today bet that Plug will keep chugging higher when earnings come out tomorrow. Image source: Getty Images.

So what

Investors (or should I say "traders") spent Wednesday trying to front-run Plug Power's Q4 earnings report, capitalize on Plug's astounding fall in price earlier this year (the stock's down about 18% from Jan. 1), and buy before the stock gets a chance to go back up. Of course, they're forcing the stock up in the process. But was buying Plug stock before tomorrow's update the right move to make?

According to analysts quoted on Yahoo! Finance, Plug's update tomorrow aren't exactly going to be of the "good" variety. Although the company is expected to report a narrower loss than it did in Q4 last year, losses per share are still expected to be about $0.07, diluted. Sales, predicted to come in at $32 million, should be down year over year -- about 2%.

Now what

Whether Plug Power thinks it can beat those estimates is something we'll know in just a few hours. Meanwhile, if you missed out on Plug's run-up by not buying Wednesday, don't fret. You could easily end up missing out on Plug stock's sell-off tomorrow, which wouldn't be so bad.

Worst case, you wait a few hours, and then make an informed decision on whether Plug's update will be good enough to justify your investment. The other guys didn't do that today, and they'll have to live with that decision tomorrow.

Rich Smith has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.