Buy SPY by Jan 29, 2031.

We often hear the standard advice: "Own more bonds to stay safe." Or the classic "100 minus your age" rule. But as a data-focused analyst, I’ve always found the standard economic models (like Mean-Variance Optimization) frustrating because they fail to mathematically support long-term stock holding. Standard models penalize stocks for "upside volatility," even if that volatility results in massive wealth generation. I recently did a deep dive into a landmark paper from the *Journal of Finance* titled **"Bond versus Stock: …