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What: Shares of Riverbed Technology, (UNKNOWN:RVBD.DL) jumped 16% Friday after activist investor Elliot Associates disclosed it has obtained a 9% stake in the wide area network specialist and will push it to find ways to increase shareholder value.

So what: Specifically, Elliot Associates stated it believes Riverbed Technology stock is "significantly undervalued," especially considering Riverbed possesses "extremely loyal customers" and "occupies a mission-critical position in thousands of networks." What's more, Elliot believes Riverbed should implement a strategic review to decide how to best optimize its operations and capital structure in a way that maximize shareholder returns.

Now what: Riverbed Technology, for its part, elaborated further in a subsequent SEC Filing, saying "Elliott believes that these initiatives will prudently, but significantly, provide a meaningful increase to the company's valuation. We have detailed these observations to the Board of Directors of [Riverbed] and look forward to a constructive dialogue."

Fool contributor Steve Symington has no position in any stocks mentioned. The Motley Fool owns shares of Riverbed Technology. 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.