Diversifying across bets that are 60 percent correlated reduces risk by only about 15 percent, perhaps slightly more.

Judge against standard portfolio mathematics: for equally weighted bets of equal volatility with pairwise correlation ρ=0.6, the ratio of portfolio risk to single-bet risk is sqrt(ρ+(1−ρ)/N). Use the number of bets N given in the context of the statement; if no N is given, use the range from a few bets up to the many-bet limit. Dalio's own chart can also settle it if it applies this same framework. TRUE: the implied risk reduction is about 15%, allowing for 'a little bit more' (roughly 12–23%). MOSTLY TRUE: the reduction is within about 10–27%. MIXED: the correct figure depends heavily on N, and the claim holds only for some plausible N. MOSTLY FALSE: the correct reduction is substantially different (for example 30–40%). FALSE: the math shows a far different reduction (for example over 40% or under 5%).

Set before the research began.

1. E1 Diversification — Risk & Portfolio Pattern Is Everything · 2 October 2026

   “The 1/√N rule only holds for uncorrelated assets; with correlation there is a floor (σ√ρ, here 16.4%) that no number of similar stocks removes.”

2. E2 Diversification — Risk & Portfolio Pattern Is Everything · 2 October 2026

   “Stocks that are each 30% volatile, with an average correlation of 0.3, held in equal weights. One stock: 30%. Five: 19.9%. Twenty: 17.4%. A hundred: 16.6%. Ten thousand: 16.4%.”

E1 and E2 describe the framework the criteria require. With pairwise correlation ρ, the volatility of an equal-weight portfolio falls toward a floor of σ√ρ that no number of assets removes. The surrounding text describes adding bets from a second up to a thousand, so the relevant range runs from a few bets up to roughly the many-bet limit. With ρ=0.6, the formula sqrt(ρ+(1−ρ)/N) gives a risk reduction of about 14% at N=3, about 18% at N=5, about 20% at N=10, and about 22.5% at the limit (√0.6≈0.775). That range sits within the 12–23% band the criteria set for "about 15 percent, maybe a little bit more", so the claim holds.