At a glance: Principal Financial Group Inc.

2001 revenue: $8.8 billion 2000: $8.9 billion 52-week high: $31.50 P/e: 19.50 Price/book: 1.47

2001 earnings: $358.8 million 2000: $620.2 million 52-week low: $20.40 Market cap: $9.68 billion

Trading volume for the Des Moines, Iowa, insurer took off Wednesday, with more than 6.8 million shares exchanging hands – more than four times its average of about 1.5 million.

The reason? Principal was one of seven new companies added to the Standard & Poor’s 500 stock index after Tuesday’s market close.

S&P pulled seven overseas companies from the benchmark and replaced them with U.S. firms, also including Prudential Financial Inc. of Newark, N.J., and Goldman Sachs Group Inc. of New York. The S&P 500 is looking to make its index a better guide to the performance of domestic large-cap stocks.

In a week when the broad market was battered, Principal Financial gained 7%, rising to $29.70 per share.