Investor confidence has edged lower in the past few months, with the looming election and high priced assets seen making people a shade more cautious.
The ASB survey shows net confidence - the difference between the optimists and pessimists - fell two percentage points to 23 percent in the three months to June, compared to a net 9 percent a year ago.
ASB senior economist Chris Tennent-Brown said greater uncertainty, both political and investment, is probably behind the easing in sentiment.
"It's understandable to see some caution in the market as people ponder policies that will impact them, such as changes in the retirement age and tax rates, as well as the various policies that could impact the housing market."
Assets such as property and shares also had high valuations, which would have investors thinking recent gains would not continue, he said.
Property was favoured as the investment giving the best returns, followed by term deposits and KiwiSaver.
Mr Tennent-Brown said the relatively high level of preference for term deposits also showed investors looking for safety, even though other types of investments offered better returns.