What assets can I invest in with a Solo 401k? Are there any limitations or restrictions?

• Solo 401(k) plans offer more flexible investment options than company-sponsored 401(k)s. Most people turn to stocks, mutual funds, and bonds, but additional opportunities exist in real estate, precious metals, foreign currencies, and more. Owners can act as plan trustees to choose and invest in funds from a number of different categories to maximize retirement savings. Very few types of investments are expressly prohibited.