Affluent investor confidence has reached its highest level in three years.

According to a monthly survey by Spectrem group released Wednesday, the Spectrem Affluent Investor Confidence Index rose five points in January to negative–three, its highest level in more than three years.

This gain in the affluent index, which measures the investment confidence and outlook of households with $500,000 or more in investable assets, kept the index in neutral territory and brought it to its highest level since December 2007.

Meanwhile, the Spectrem Millionaire Investor Confidence Index fell five points in January to two, also a neutral reading.

“Affluent investors rang in the New Year with a noteworthy gain in investment confidence, taking their January outlook to its highest level in more than 3 years,” said George H. Walper, Jr., Spectrem Group’s president. “This brought their confidence more in line with the traditionally more optimistic millionaires, whose outlook waned.  Nevertheless, both groups have made strong gains since late summer and seem poised for more should the economy and stock market continue to cooperate,”

In response to an open-ended question about the one factor most affecting their investment plans, affluent investors in January cited: stock market conditions (25%); the economic environment (22%); retirement (10%); household income (9%); the political climate (2%); and household cash flow (2%). Those choosing stock market conditions rose from 21% in October 2010, the last time this question was asked, and those citing the economic environment advanced from 20%.

Millionaires were more focused on both stock market conditions (29%) and the economic environment (24%) than the affluent.