US stocks fell on Friday, as investors focused on the worst in a mixed bag of corporate earnings news, selling shares after big rallies this week inspired by news of the Federal Reserve's surprise interest rate cut at midweek.

Of the 30 Dow stocks, pharmaceutical giant Merck & Co. Inc. fell the most, dropping $4.66, or 6 percent, to $73.61, after posting an 11 percent gain in first-quarter profits. But the statement included sales figures that some investors thought were disappointing.

The recent rally had, before Friday, sent the tech-packed Nasdaq soaring 33 percent since hitting its lowest level in more than two years on April 4th. Stocks had bolted higher on Wednesday after the Federal Reserve unexpectedly lowered interest rates. The move sent investors scrambling back into the high-tech sector.