February 13, 2026: Diversification is the Only Free Lunch in Investing

I hesitate to talk about “free lunch” when it comes to investing. It’s simply hard to say it with a straight face. However, I feel comfortable saying it when the quote is attributed to Harry Markowitz.

Markowitz coined, “Diversification is the only free lunch in investing.” His belief was that diversification can provide a critical feature to an investment portfolio if done correctly: reducing risk (volatility) of a portfolio without reducing returns. This is a known and documented phenomenon. By adding assets to a portfolio that are not correlated 1:1, the return of a diversified portfolio can be maximized given a certain level of risk.

Think of this simple example: would you rather have a portfolio return 6% that is highly risky (volatile) or less risky? Easy - the answer is “less risky.” I will never say “risk-free” because it just isn’t possible.

Why should we believe Markowitz? Draw your own conclusions, but Markowitz was a Nobel Laureate and pioneer of Modern Portfolio Theory. Modern Portfolio Theory provides a scientific basis for why diversification works.

Is it a free lunch? I agree with Markowitz’s assessment with only one caveat and I’ll demonstrate with another example. It’s not a matter of math, but of human psychology.

You diversify your portfolio among domestic stocks, bonds, international stocks, commodities, real estate, etc. You will notice one infuriating fact about your portfolio: it will always underperform the best-performing asset in the portfolio. You will be frustrated that the best-performing asset (say you only focus on NVIDIA stock since it makes headlines frequently) is up 20% while the portfolio is up “only” 8%. Then you’ll ask yourself, “Why didn’t I just go all-in? Who needs diversification if the returns are lower than NVIDIA stock?”

You’ll probably forget all the times your portfolio was down less than the worst-performing asset, even though you were thankful in the moment (NVIDIA once plummeted 17% in a single day and wiped out $600 billion of value). The more severe your losses, the greater the gain you need to make it back. A 50% loss requires a 100% gain to get back to breakeven.

Remember, the goal isn’t to seek the highest returns. The goal is to seek the highest risk-adjusted return aligned with your risk tolerance and time horizon, but the nuance is lost on most people.

Can you stick with diversification? It’s harder than it sounds. But if you want a “free lunch” then maybe you should.