The Nasdaq 100 index (.NDX) closed up 0.3 percent at 4,719.05, surpassing for the first time levels reached during the dot-com boom in 2000. The S&P energy sector (.SPNY) rose 2.5 percent, its fifth straight daily increase, as crude prices rallied. While energy stocks have risen about 22 percent since late August, the sector is still down roughly 10 percent year to date.