NEW YORK (TheStreet) - This week's biotech-led selloff in stocks is paving the way for buying opportunities down the road, one strategist says.  A key indicator to watch is the S&P 500, currently around 2,051.

"S&P at 2,035 seems to be an attractive entry point on this pullback," said Mark Luschini, chief investment strategist at Janney Capital Markets. "The selloff started because investors finally woke up to the fact that valuations are full and recent economic data has been anything but encouraging."