The primary decision-makers for mass-market 401(k) plans are often HR or finance teams, not investors. To shield their companies from employee lawsuits, they have historically prioritized funds with the lowest fees, creating a massive structural barrier for higher-fee alternative investments to gain traction.

The term "Solo 401(k)" is a misnomer; it can be used by any business with no non-owner employees. This means a partnership with several partners, and even their spouses, can all participate in the same plan. Each individual becomes eligible for their own contribution limit, assuming company income is sufficient.

Once a Solo 401(k) plan's assets exceed $250,000, the owner must file Form 5500-EZ annually. Failure to do so incurs steep penalties of $250 per day, up to $150,000. While the form is simple, this compliance requirement is often overlooked, and regulatory enforcement has recently increased.

If a former employer has gone out of business, your old 401(k) isn't necessarily lost. You can use free resources like the National Registry of Unclaimed Retirement Benefits and the Department of Labor's database to track down these abandoned accounts.

For business owners with high income and few or no employees, a defined benefit pension plan can offer significantly larger tax deductions than standard retirement plans like a 401(k), potentially allowing for write-offs exceeding half a million dollars.

A crucial wealth protection strategy is to never hold investment assets, like rental properties, in your personal name. By placing them in an entity like an LLC or trust, you create a legal shield. In a lawsuit, only the entity's assets are at risk, not your personal wealth.

While DC plans receive huge inflows, a large portion of assets leaks out annually into rollover IRAs as employees change jobs. This dynamic means the net growth of the captive 401(k) asset pool is less explosive than top-line numbers suggest, tempering the "flood of capital" narrative for private markets.

The Mega Backdoor Roth strategy works perfectly for solo practitioners and owner-only businesses. A solo 401k plan is exempt from the complex compliance testing and administrative burdens that often prevent larger companies from offering the feature, making it an especially powerful and streamlined tool for the self-employed.

Many don't realize the $72,000 annual retirement contribution limit applies per plan, not per person. A solo practitioner with a side business can max out their primary employer's 401(k) and still contribute up to another $72,000 to a separate Solo 401(k) or SEP IRA, provided their side income is sufficient.