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Stock markets once again finished the week on a mixed note, with the Dow losing ground even as the broader S&P 500 and Nasdaq Composite posted modest gains on the day. The news of the day was a potential game changer, with poor jobs growth raising questions about whether the Federal Reserve's assessment of an improving economy will prove justified by future economic performance. Still, even with hesitation within the market at large, Intuitive Surgical (NASDAQ:ISRG), Zale (UNKNOWN:ZLC.DL), and Abercrombie & Fitch (NYSE:ANF) all posted substantial gains Friday.

Intuitive Surgical rose 9%. Yesterday, the company released findings from a study showing that robotic-assisted prostatectomy showed favorable results compared to traditional open surgical procedures, including fewer complications and shorter hospital stays. These findings are consistent with early results comparing robotic surgery to alternatives, but the results are more important after concerns called the safety of robotic surgery into question. Moreover, as virtual reality technology becomes more advanced, Intuitive Surgical could see greater demand as doctors get more comfortable with the concepts involved.

Jewelry retailer Zale finished up nearly 15% after announcing favorable results this morning for its holiday season. The jeweler said that comps rose 2% after adjusting for exchange-rate changes, although revenue fell in dollar terms. Investors were especially pleased that the company managed to boost its gross margin by two full percentage points, with half of that gain falling through to operating margins. Given the high levels of promotional activity among retailers in 2013, it was encouraging for Zale to do as well as it did.

Abercrombie & Fitch rose 12% after the long-slumping teen retailer finally gave investors the update to the holiday quarter they'd hoped to see. Comparable-store sales for the nine-week period ending Jan. 4 showed a drop of just 6%, with a sharp 25% increase in direct-to-consumer sales helping minimize the declines for the teen retailer. Combined with a $0.15 per-share increase in its projected range for adjusted earnings per share, A&F has investors hoping that it has hit bottom and is starting to recover from its worst times.

Fool contributor Dan Caplinger has no position in any stocks mentioned. You can follow him on Twitter @DanCaplinger. The Motley Fool recommends Intuitive Surgical. The Motley Fool owns shares of Intuitive Surgical. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.