After dropping eight points in November, the Spectrem Millionaire Investor Confidence Index rebounded four points in December to reach -2, according to the latest report from Lake-Forest, Ill.-based consulting firm Spectrem Group.

Year-end jitters over issues such as the fiscal cliff had worn off some, according to the report, which measures attitudes of wealthy investors each month.

“Concerns about the Political Climate were not enough to keep Affluent investor confidence down in December,” Spectrem said.

Spectrem described the mood as “cautiously positive,” as millionaire households began rolling back into stocks after a reported two-month decline. Planned investment in stocks rose 1.80 points to 30.6 in December due to an increase in stock investments among millionaire households, according to the report.

“Millionaires, after two consecutive months of decline, got their Stock groove back on,” Spectrem wrote.

Still, many millionaires chose to “not invest,” as that preference gained 6.9 points to reach a six-month high of 32.7.

That caution in large part reflected the main issues of the day heading into the year’s end. In November, respondents indicated that their greatest investment concern was the economic impact of the fiscal cliff. In December, affluent investors reported that it was the political climate, “the factor they perceived to be the obstacle to reaching a solution,” Spectrem said.

The survey and indices are compiled from 250 monthly interviews with financial decision makers with over $500,000 in investable assets. Bands of 31 to 51 are considered bullish, 11 to 30 is mildly bullish, 10 to -10 is neutral, an outlook of -11 to -30 is mildly bearish and -31 to -51 is bearish.