To say the past five years have been cruel to Nokia (NYSE:NOK) would be something of an understatement. Since peaking in November 2007, shares have absolutely cratered, diving during the financial crisis, then never bouncing back.

At NOK’s lowest moment — when it bottomed out at $1.69 on July 17 — the stock had fallen more than 95% from its highs, and it seemed like the company was headed for oblivion.

But oh, what a month can change. Including NOK’s nearly 8% gains Monday, shares have almost doubled since July 17 and now are trading around $3.30 — their highest point since May.

So what’s behind the sudden reversal, and can investors bank on the momentum sticking around?

Well, part of Nokia’s demand has come from bargain hunters and from short covering — both short-term sparks — and some from increased bullishness in European stocks.

But something more substantive might at work: a big change in the mobile industry.

Apple (NASDAQ:AAPL) just scored a huge patent victory against Samsung, and it could be a game-changer.

The court decision will mean lots of scrambling as mobile operators find workarounds to avoid future liability exposure. No doubt, this will slowdown the momentum of the industry, at least in the short-run.

But this looks more like an issue for other phones running Google‘s (NASDAQ:GOOG) Android OS, and less a problem for Nokia. The company’s whose Lumia line has a fairly unique look and feel, not to mention it is based on Microsoft’s (NASDAQ:MSFT) Windows Phone operating system, which also is differentiated and highly protected. In fact, a Nokia phone was used by Apple as an example of technology that didn’t elbow in on its patents — patents that now seem much more valuable on the heels of such a ruling.

Nokia is expected to launch new Lumia models at its Nokia World event Sept. 5-6, which should provide some much-needed buzz.

Still, one ruling does not a turnaround make.

Nokia’s smartphones have yet to get much traction, especially in the critical U.S. market. Even if Samsung’s Galaxy III S is sidelined, it’s very likely Nokia could get overlooked as Apple launches its iPhone 5. Plus, Samsung has the resources to adapt quickly to the Apple verdict.

Despite the run, investors should be wary of Nokia. The company has had a consistently poor track record in building devices that consumers want, and there’s little out there indicating that Apple won’t continue to eat into market share.

Nokia’s stock already has enjoyed a massive rebound, with enough gains coming off hope (and not fundamentals) to make one cautious. Consider taking some profits if you bought the bottom — and if you’re not already in, stay out for now.

Tom Taulli runs the InvestorPlace blog IPOPlaybook, a site dedicated to the hottest news and rumors about initial public offerings. He also is the author of “All About Short Selling” and “All About Commodities.” Follow him on Twitter at @ttaulli. As of this writing, he did not own a position in any of the aforementioned securities.