A pair of Goldman Sachs quantitative funds, including its flagship hedge fund, has bounced back this year after a disastrous 2007.

Goldman’s Global Alpha—just one-fifth of its peak size, with about $2.5 billion in assets—is up 19% this year. The firm’s $1 billion Global Equities Opportunities Fund has returned 7% this year.

Last year, Global Alpha fell by 40%, and GEO fell by about 30%, both battered by market volatility in the wake of the credit crisis. The latter also required a $3 billion cash infusion last year.

Last week, Robert Litterman, chairman of Goldman’s quantitative investments, said the firm has learned its quant funds cannot be as large as they once were. At its peak, Global Alpha managed $12 billion, and GEO managed $6 billion.