Ultra-high-net-worth investors are decreasing their exposure to the U.S. stock market by allocating more to alternative investments, according to the Institute for Private Investors annual Family Performance Tracking survey.

In the recently released survey, 48% of respondents reported that they plan to increase their allocation to commodities this year, and 45% of respondents to real estate. Forty-four percent said they planned to increase their holdings in global equities and 36% plan to decrease their cash holdings.

According to the survey, 55% of families said that they are looking to increase direct investments in private companies. In addition, investors reported being increasingly bullish on tangible assets such as gold, land and artwork, in addition to commercial and residential real estate.

Investors expected an average return of 4.9% for their overall portfolio in 2011, compared with an average return of 11.26% a year earlier. Investor outlook for the overall market in the coming year was more positive, with respondents expecting the S&P to return an average of 6.4% this year.

This is the 13th survey by IPI. It was conducted in November and highlights the expectations, returns and asset allocations of IPI member families. The group provides investment education and networking to 1,100 ultra-high-net-worth investors, including about 345 private families. IPI member families have at least $30 million of investable assets. Four in ten families have assets of $200 million or more.