S1 Corp. ( SONE): Hedge fund investment in SONE increased dramatically during the third quarter. By the end of the quarter, 19 hedge funds had $124.76 million invested in the company, up from 14 funds with $59 million invested at the end of the second quarter. Israel Englander's Millennium Management is a fan of SONE, as is Cliff Asness' AQR Capital Management. Blue Coat Systems ( BCSI): The number of hedge funds invested in BCSI did not change during the third quarter. There were 16 funds invested in the company at the end of June, and the same number was invested in the company at the end of September. The total volume of hedge fund investment in the company nearly doubled, however, moving from $63.64 million at the end of the second quarter to $119.23 million at the end of the third quarter. Both Michael Lowenstein's Kensico Capital and Lee Hobson's Highside Capital Management like BCSI. SuccessFactors ( SFSF): The number of hedge funds invested in SFSF did not change from the end of June to the end of September, but the volume of that investment did increase. It moved from $155.64 million across 16 funds at the end of the second quarter, to $173.28 million across 16 funds at the end of the third quarter. Steve Cohen's SAC Capital Advisors, Bain Capital'sBrookside Capital and Donald Chiboucis' Columbus Circle Investors each increased positions in SFSF during the third quarter. Datalink Corp. ( DTLK): The number of hedge funds invested in DTLK doubled from the end of the second quarter, when just three hedge funds were invested in the company, to six at the end of the third quarter. Total hedge fund investment also increased, moving from just $540,000 at the end of June to $3.81 million at the end of September. Jim Simons' Renaissance Technologies, Richard Driehaus' Driehaus Capital and Israel Englander's Millennium Management are fans of DTLK.