Aquamarine Fund

Guy Spier's Aquamarine Fund is a value-investing hedge fund explicitly modeled on Warren Buffett's Berkshire approach - concentrated long-only positions in compounding businesses, held over multi-year horizons with low turnover. Spier is widely known for the 2008 $650,000 charity lunch with Buffett (purchased jointly with Mohnish Pabrai) and the resulting investing memoir 'The Education of a Value Investor.'

The Aquamarine book reflects the value philosophy: small position count (typically under 25), concentrated weights, mostly mid-and-large-cap US equities, with selective international exposure. The fund does not chase thematic narratives or sector rotations - the positions are individual-stock-pick driven, with each name justified on intrinsic-value-and-margin-of-safety grounds. Holdings rotate slowly enough that quarter-to-quarter 13F deltas are typically small.

For retail traders, the Aquamarine 13F is a useful snapshot of a Buffett-style book at a size where individual position changes are more readable than at Berkshire's massive scale. Spier's positions also overlap meaningfully with the Pabrai Funds book (they share investing-circle origins and overlapping research processes), so the two 13Fs read as a paired signal on the value-style segment of the market.