What is the 70 30 rule Warren Buffett?

Warren Buffett’s 70/30 Rule: A Glimpse into His Early Strategy

Long before Warren Buffett became synonymous with value investing, he laid the groundwork for his legendary approach in a 1957 letter to his limited partners. In that letter, he outlined what some now refer to as the “70/30 rule”—a strategic allocation where 70% of the partnership’s capital was invested in undervalued stocks, and the remaining 30% was dedicated to corporate work-outs.

This wasn’t a rigid formula, but rather a reflection of Buffett’s early investment philosophy. The 70% in stocks focused on companies trading below their intrinsic value—what Buffett, a disciple of Benjamin Graham, called “cigar butt” investing: picking up cheap, overlooked opportunities with a bit of value left in them. The other 30% was deployed in what Buffett described as “work-outs”—situations involving mergers, bankruptcies, reorganizations, or liquidations, where the outcome could be predicted more from corporate action than market sentiment.

Unlike modern portfolio theories that emphasize diversification and market timing, Buffett’s split was pragmatic and opportunity-driven. He wasn’t chasing balance for balance’s sake—it was about where he saw the clearest edge. The 70/30 split allowed him to stay mostly invested in the market while keeping dry powder for complex, event-driven plays that others might overlook.

Interestingly, this approach highlights a lesser-known side of Buffett—one more active in arbitrage and special situations, before he shifted toward buying high-quality businesses for the long term. While the 70/30 rule isn’t a current mandate at Berkshire Hathaway, it remains a telling snapshot of Buffett’s evolution: from a Graham-inspired bargain hunter to a patient capitalist building enduring value.

It’s a reminder that even the most steadfast principles in investing often begin as flexible experiments—tested, refined, and adapted over time.