Sapient shares soared up 18 5/8, or 23 percent, to 98 Thursday after the Internet consulting firm was added to the S&P 500 Index.
Sapient (Nasdaq: SAPE) will replace Reynolds Metals (NYSE: RLM) after the bell.
In its latest quarter, Sapient beat the Street estimate by 2 cents a share, earning $12.7 million, or 19 cents a share, on sales of $100.3 million.
That $100.3 million in sales marked a 74 percent improvement from the first quarter of 1999.
First Call Corp. consensus expects the company to return a profit of 20 cents a share in its second quarter and 83 cents a share in the fiscal year.
Its shares peaked at 151 3/16 in January after falling to a 52-week low of 23 7/8 in July.
All 19 analysts covering the stock maintain either a "buy" or "strong buy" recommendation.