Investor confidence nosedived over the last month as uncertainty  over the fiscal cliff and potential tax and spending cuts took its toll on wealthy investors.

Posting its largest month-to-month drop since June 2011, Spectrem’s Affluent Investor Confidence index, which reflects the opinion of those with over $500,000 in net worth, fell 11 points, to -13, its lowest point so far in 2012. Millionaire investors alone reported an eight point drop to -6.

“This setback in affluent investor confidence was perhaps precipitated by increased concerns over the looming fiscal cliff, the tax cuts and mandatory spending cuts scheduled to take effect at the end of the year if a bipartisan solution towards solving the nation’s deficit is not reached,” Donald Liebenson of Spectrem’s Millionaire Corner.

Nearly half, 48%, of the respondents said that news on “the political environment” was most affecting their economic outlook and almost a third, 32%, cited the fiscal cliff of economic policy changes slated to take effect come 2013.

The survey also showed a rising demand for some traditionally safer investment options. Affluent investors increased their stake in Bond Mutual Funds and Cash, and a larger number reported that they were staying out of the market.

The survey and indices are the result of 250 monthly interviews with financial decision makers with more than $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.