Reflecting a slow return of investors’ risk appetite, long-term U.S. stock and bond funds took in $34 billion in inflows in January, Strategic Insight said.

This was an improvement from the $16 billion they netted in December.

Of the January flows, $21 billion went to U.S. equity funds, which could portend a stronger year for U.S. equity funds, Strategic Insight said.

This was the first month of positive flows to U.S. equity funds since April, just before the May 6 Flash Crash, when investors put $11 billion into U.S. stock funds. It was also the first time that monthly flows to the category topped $20 billion since February 2004.

“The interest in stocks is being shored up by a new year, stock prices which have doubled since their bottom in early 2009, and a near consensus about the relative advantage of U.S. large-cap stocks,” said Strategic Insight Director of Research Avi Nachmany. “Looking ahead, up-trending economic and employment indications should further improve investors’ sentiment.”

Strategic Insight projects equity fund sales growth of 22% in 2011.