Davide Semilia @DavideSemilia: "Owning 30 stocks doesn't make..."

Italy

Owning 30 stocks doesn't make you diversified You've heard it a thousand times: just buy more stocks and you'll be safe. Spread your money across 30 names and sleep well at night. It sounds logical. More stocks, less risk. Your finance professor probably drew a chart showing how volatility drops as you add holdings. And technically, that chart is correct. But here's what nobody tells you. Most retail investors who own 30 stocks actually own the same stock 30 times. They hold Apple, Microsoft, Google, Amazon, Meta, Nvidia, and then 24 more tech-adjacent growth names that all move in lockstep. In March 2020, their "diversified" portfolio dropped 35% in three weeks. In 2022, it dropped 30% again. Every single time, everything fell together. The math is brutal. Correlation between S&P 500 stocks during crashes averages 0.85. That means when it matters most, your 30 stocks behave like one stock. Diversification disappears exactly when you need it. Real diversification isn't about counting holdings. It's about owning assets that disagree with each other. Commodities when stocks fall. Short-duration bonds when long-duration gets crushed. Energy when tech bleeds. International value when US growth stalls. I learned this the hard way in my own portfolio. Adding a 31st tech stock did nothing. Adding one uncorrelated position changed everything. The uncomfortable truth: genuine diversification means always having something in your portfolio that embarrasses you. If everything is going up at once, you're not diversified. You're just concentrated with extra steps. $AAPL (Apple) $XLE (State Street Energy Select Sector SPDR ETF) $GLD (SPDR Gold) $EEM (iShares MSCI Emerging Markets ETF) $TLT (iShares 20+ Year Treasury Bond ETF )

Not investment advice. The author may have financial interests in the mentioned instruments.