The Spectrem Millionaire Investor Confidence Index fell to its lowest level in more than a year in August as wealthy U.S. investors worried about politics and unemployment, according to Spectrem Group.

The index fell 11 points in August to -18, its lowest level since June 2009, when it fell a record 18 points to -20 shortly after the S&P 500 index hit a 12-year low.

The move returns the index to mildly bearish territory after 12 straight months in neutral.

The Chicago-based consulting firm, which specializes in affluent and retirement markets, defines neutral as between -10 and +10 in the index, which ranges from -100 to +100.

“The millionaires’ decline is particularly troubling since it suggests millionaires, typically more sophisticated than the broader affluent population, are reverting to a bearish frame of mind,” said George Walper, president of Spectrem Group.

At the same time, the Spectrem Affluent Investor Confidence Index, which measures the outlook of households with $500,000 or more in investable assets, fell 4 points in August to -20, its third-straight monthly decline.

In response to an open-ended question about the factors most affecting their economic outlook, 18 percent of affluent investors cited the political environment, up from 13 percent last month, while 16 percent cited unemployment, up from 6 percent.

U.S. mid-term elections are coming up in November. Many affluent investors are worried that Bush-era tax breaks for investors will be allowed to expire at the end of the year, significantly increasing dividends tax.

Millionaires were more focused on the political environment, with 25 percent of respondents citing that, but less focused on unemployment, with 13 percent citing the labor market.