The Holy Grail of Investing: 15 Uncorrelated Return Streams
Dalio discovered this after being wiped out in 1982. He had bet big on a debt crisis, was right about the mechanics, wrong about the timing, lost money for himself and his clients, and had to borrow $4,000 from his father to keep going. The experience forced him to answer one question: how do you keep the upside without suffering the downside? The answer was math, not intuition. He mapped the marginal benefit of diversification against correlation levels and found a specific number. He says: "Find 15 good uncorrelated return streams. If you can get out to 15, you can reduce about 80% of your risk without reducing your return. That means you increase your return-to-risk ratio by something like a factor of five." Most investors diversify across assets that move together, which offers the feeling of diversification without the math. The key word is uncorrelated. Two positions in the same sector, or two assets that both fall in a liquidity crunch, do not count as two streams. The exercise is to audit whether your positions actually move independently of each other under stress, not just in calm markets.