Chicago-based affluence and retirement consultancy Spectrem Group has seen both its Millionaire Investor Confidence and Affluent Investor Confidence indices fall 2 points in October after three months of straight rises.

Despite the October drop, the millionaire index remains in neutral territory for a third month; the AI index, which measures the investment confidence of households with $500,000 or more in investable assets, stays in mildly bearish territory.

In response to an open-ended question about the one factor most affecting their investment plans, affluent investors in October cited stock market conditions (27 per cent) and the economic environment (22 per cent); a few cited retirement, household income or household cash flow.

Millionaires expressed more concern about the stock market (29 per cent) than the affluent, but were slightly less concerned about the economy (20 per cent).