(Bloomberg) -- Stocks and other assets are priced at unrealistic levels based on the outlook for global growth, according to billionaire bond guru Bill Gross.

"Equity markets are priced for too much hope, high yield bond markets for too much growth, and all asset prices elevated to artificial levels that only a model driven, historically biased investor would believe could lead to returns resembling the past six years," Gross, manager of the Janus Global Unconstrained Bond Fund, wrote in a monthly investment outlook released Thursday. "High rates of growth, and the productivity that drives it, are likely distant memories from a bygone era."

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