You had a pretty good move in biotech this year, and biotech really has quite frankly lifted the health care and the drug stocks recently because investors have become somewhat defensive -- say in the last month or so -- and have also, on a relative basis, performed fairly well.
There's fairly widespread anticipation that the economic numbers this week will be solid, though not great, and I think the market is reflecting that.
The combination of a decline in oil prices, however slight, and some fairly upbeat comments (by Fed officials), may have led Fed watchers to conclude the Fed may raise interest rates at its meeting in May, and then stop.