Wall Street’s largest firms are championing a new cause. They are bringing alternative assets — once reserved for the ultra-wealthy — to the portfolios of individual investors. Chief among the proponents are BlackRock and Goldman Sachs. But, as is usually the case in investing, the potential of greater returns comes at a risk. “The alternative market is becoming less alternative,” said Jon Diorio, head of alternatives for wealth at asset management giant BlackRock. Alternatives are assets outside of stocks, bonds, and cash — including private equity, private credit, real estate, infrastructure, cryptocurrencies, and more. “It’s growing very rapidly as public markets are shrinking,” Diorio told CNBC in a recent interview. Interest has been fueled by shrinking public market opportunities and a softening regulatory environment. President Donald Trump signed an executive order earlier this month that paved the way for alternative assets in 401(k) retirement accounts — an idea vehemently opposed by the Biden administration. Diorio, who also leads product strategy for BlackRock’s U.S. wealth advisory business, said that giving more investors exposure to alternatives — which have traditionally been part of the portfolios of ultra high net-worth individuals, hedge funds, and pension funds — can improve returns over the long run. “In some cases, you can get enhanced diversification [and] amplify return streams,” he added. Giving individual investors the same access to different asset classes as the …