The end of December was a "dud" for flows into equity mutual funds, reports Jeff Tjornehoj ofLipper.

According to Lipper data, equity fund investors dumped $3.5 billion in assets during the last week of December. The cause? The debate over the fiscal cliff and perhaps last-minute tax selling, Tjornejoj said.

Domestic equity funds "bore the brunt" of the selling, with over $3.6 billion in net outflows as investors sought better opportunities in Latin America Funds ( $115 million) and Emerging Markets Funds ( $220 million). High-yield funds had outflows of $282 million, while loan participation funds managed to real in $241 million.

Not all funds suffered from overall outflows. Money market funds enjoyed top honors for the week with $37.8 billion in flows thanks to institutional investors adding $21.6 billion to their accounts — retail investors added $16.2 billion into theirs. ETF investors also added $7.1 billion to their equity choices, led by SPDR S&P 500 ETF (SPY) with $3.8 billion in net inflows.

Meanwhile, taxable bond mutual funds had "very modest" inflows of $83 million, and municipal debt funds lost $6 million.