Indices of investment opinions of high net worth and affluent individuals, as tracked by the US-based Spectrem Group, showed mixed readings in February, new data showed.

The Spectrem Affluent Investor Confidence Index rose by 3 points in February to –10, returning to what Spectrum says is neutral territory. Answers can range from 100 to -100 on a range from extreme optimism to pessimism.

The increase in the affluent index, which measures the investment outlook of households with $500,000 or more in investable assets, follows a 2-point advance in January 2010, Spectrem said.

It brings the index to neutral from mildly bearish for only the second time since February 2008. The index was last neutral in November 2009.

The Spectrem Millionaire Investor Confidence Index fell 1 point in February to –10, its seventh-straight neutral reading.

“Affluent Americans became slightly more confident about investing in February as millionaires saw their confidence slip. This left both groups with identical confidence readings – an unusual situation since millionaires have historically been more optimistic than the affluent – suggesting deep-seated unease among millionaires about both the economy and issues surrounding it,” said George Walper, president of Spectrem Group.