The reason biotech stocks - fine names at great prices - are down is simple. Sector rotation.Gilead Sciences $GILD, Regeneron $REGN, and Biogen $BIIB close at new lows daily despite fundamentally good news each time.Investors have moved into oil and gas. The rally in energy, now that oil prices are so high, Iran is/will be sanctioned, and U.S. produces its own energy, $BP, Exxon $XOM, are up.Will it last? Value Investors don't know. We cannot forecast the future.At these levels, the biotech picks are on sale. Eventually, the gap to fair value will get filled. That will be a big pay day for patient investors. $REGN, Regeneron Pharmaceuticals, Inc. / H1 $GILD: $GILD, Gilead Sciences, Inc. / H1 $CELG: $CELG, Celgene Corporation / H1