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What: Shares of specialty foundry Tower Semiconductor (NASDAQ:TSEM), which operates under the brand name TowerJazz, jumped more than 20% on Monday morning after the company reported its fourth-quarter earnings, beating analyst estimates.

So what: Tower reported revenue of $235 million for the fourth quarter, up 75% year-over-year and just ahead of analyst estimates. Non-GAAP EPS of $0.83 easily beat analyst estimates of $0.58, and GAAP EPS swung from a loss of $0.62 during the fourth quarter of 2013 to a gain of $0.01.

On a GAAP basis, gross margin rose to 16.2% during the quarter, up from just 6.6% during the fourth quarter of 2013. For the full year, Tower grew revenue by 64%, posting a GAAP operating loss of $103 million, nearly doubling year-over-year. GAAP EPS was positive only due to a $166 million gain from an acquisition.

Tower guided for $225 million in revenue for the first quarter of 2015, representing about 70% year-over-year growth. The company provided no guidance for earnings in its press release.

Now what: From 2004 through 2013, Tower Semiconductor posted a GAAP net loss during every single year. While 2014 seems to reverse this trend, a combination of booking a gain from an acquisition and a large tax benefit greatly skew the results. Backing out these items, as well as a $55 million restructuring charge, leads to a larger net loss in 2014 compared to 2013.

There doesn't appear to be any evidence that Tower Semiconductor is capable of producing a real profit. While Tower did better during the fourth quarter than analysts were expecting, it's still a money-losing company in a capital-intensive business. Investors considering buying shares of the company should first take a very deep look at its financials.