Renaissance Technologies, one of the best performing quantitative hedge funds, is opening a new fund to the tune of $100 billion.

Renaissance Technologies Corp., a top-performing hedge fund group headed by billionaire James Simons, has amassed $8.5 billion for a new computer-driven hedge fund it says could handle $100 billion, a person familiar with the situation said on Wednesday.

The new "quantitative" fund, which started last year, has doubled in asset size since February, the source said, largely on the promise that Renaissance can generate sustainable high returns through complex math-driven strategies developed by Simons over several decades.

The new Institutional Equities Fund is up 21 percent in the year to date, net of fees, the source said, a promising start that continues to bring in new investors from a wide array of pension funds, endowments and other institutions.

I'm surprised the new fund claims to be able to take $100 billion dollars. Gains from trading are usually limited when you reach such high levels of capital.