Investor confidence among millionaires rose to its highest level in more than two years as optimism about the economy increased.

The Spectrem Millionaire Investor Confidence Index rose five points this month to negative-one, according to a monthly survey by Spectrem Group, a Chicago research firm, released Wednesday. This is the ninth-consecutive neutral reading and the highest level since December 2007.

Meanwhile, the Spectrem Affluent Investor Confidence Index, which measures the investment confidence and outlook of households with $500,000 or more in investable assets, rose three points in April to negative-nine.

This neutral reading is the index's highest since December 2007.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.