Hedge fund honcho runs Highbridge Capital with grade-school buddy Glenn Dubin. Investments soured when computer-controlled quantitative fund lost 14% last year. Rebound: quant fund up 15% this year. Firm's flagship fund returned 8.5% net of fees in 2007. Founded Highbridge hedge fund and private equity outfit in 1992. Sold 55% stake to JPMorgan in 2004 for more than $1.3 billion; duo still controls investment decisions. Assets flat in past year at $28 billion. Swieca: on executive committee of pro-Israel lobby American Israel Public Affairs Committee.