What is the 70/30 Buffett rule investing?

Asked "What is the 70/30 Buffett rule investing?", ChatGPT, Copilot, Gemini, Google AI Mode and Perplexity named 9 distinct names across 5 answers on September 7, 2026, and 2 of them in two or more answers, and the engines did not agree; the closest to a consensus, Vanguard, was named by only 2 of 5.

Measured acrossChatGPTCopilotGeminiGoogle AI ModePerplexity

2 of 9 names confirmed · named in 2 or more of 5 answers · asked September 7, 2026 · 5 engines

The 70/30 Buffett rule is a guideline for allocating 70% of a portfolio to stocks for long-term growth and 30% to safer assets like bonds or cash for stability, although it is not a rigid formula prescribed by Warren Buffett himself. The rule has its origins in Buffett's 1957 description of his investment partnership's mix of 70% in undervalued general stock issues and 30% in work-outs, which has been misinterpreted over time as a 70/30 stock/bond split. In reality, Buffett has suggested simpler allocations, such as 90% in an S&P 500 index fund and 10% in short-term government bonds, for non-professional investors.

1Vanguardnamed in 2 of 5 answers
2Investopedianamed in 2 of 5 answers
3Webullnamed in 1 of 5 answersone answer
4Nasdaqnamed in 1 of 5 answersone answer
5Yahoonamed in 1 of 5 answersone answer
6Morningstarnamed in 1 of 5 answersone answer
7S&P 500named in 1 of 5 answersone answer
8Smartdishanamed in 1 of 5 answersone answer
9Smartassetnamed in 1 of 5 answersone answer

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The full measurement

The position each of the 5 engines gave all 9 names.
How many of the 5 answers named each of them.
5 sampled observations behind this ranking, and where the engines disagree.
Fan-out — the query each engine actually searched.
Every citation, and the sources nobody cited.

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