(CBS) — Stocks closed higher Friday, wrapping up their best weekly performance in months, as investors re-position themselves ahead of earnings season.

The S&P 500 added 1; the NASDAQ gained 20 and the Dow Jones Industrial Average closed up 34 points, settling to 17,084.

“It seems the recent rally in stocks started last Friday after a big reversal day and that just sent a shudder through some of the bears and especially those on the short side of the market,” says Chuck Carlson, CEO of Horizon Investment Services.

“When you see the markets behave the way they did in the face of seemingly really bad news, it often indicates a market that is bottoming or has in fact has already bottomed.”

He adds that the Dow Theory, a trusted market timing system, has now turned bullish.