Both stocks and bonds have struggled this year, leaving investors with few alternatives.
Stocks and bonds usually move in opposite directions, but that hasn't been the case this year.
Trend-following strategy Adopting the so-called trend-following strategy this year would pay off for investors, according to Goldman and Wells Fargo in recent notes.
Portfolio diversification can, and often should, include more than stocks and bonds," said Hazlitt Gill, retail investment research senior manager.
Alternative investments UBS in an Oct. 21 note said investors can use structured investments to "tilt the odds favorably."