Shares of QlikTechnologies, a Radnor-based data-visualization software company, jumped more than 7 percent in trading today after Elliott Management Corp. a New York-based hedge fund manager headed by billionaire investor Paul Singer, said its affiliates bought an 8.8% stake (now worth over $200 million) in Qlik, and are pushing for changes such as a sale, cost-cutting or other moves that might enrich Singer and other Qlik shareholders.

In this document filed with the Securities and Exchange Commission, Elliot said QlikTech shares are "significantly undervalued," and fail to reflect the company's "highly strategic" markets, "attractive competitive position" and "compelling product set." Singer and his allies see "strategic and operational opportunities for (QlikTech) that would meaningfully increase value to shareholders," and have met with QlikTech bosses and board members to push their agenda, the statment adds.

Qlik, under the leadership of Lars Bjork (corrected, thanks A.D.), has its software development offices in Sweden and runs sales and other business functions from the Main Line. The company competes with Tableau and other business data-visualization software providers, and against Oracle, SAP and other corporate software giants.

With the rapid growth in sales of systems that help companies pump useful data to employees via smartphone, data-visualization stocks have traded at high prices, but they have been volatile, subject to big changes as profits and prospects shift. Qlik shares traded above $40 last summer but fell below $20 in mid-February.

Singer polished his reputation as an aggressive investor with his 2012 seizure of an Argentine Navy training ship in Africa in an effort to collect on defaulted bonds. His recent tech targets include Compuware and Novell. He also owns valuable holdings in Cabela's, the hunting store chain, Interpubllic, the ad agency, and Comcast, the cable company, among others.

A spokesman for Elliott had no immediate comment. Qlik officials said the company was preparing a response.