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| Quarter | Letter Date | Fund Name | QTD | YTD | Tickers | Themes | Quick Take |
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"Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on high-quality compounders."
In his 2025 annual letter, Guy Spier announces the difficult decision to close the Aquamarine Fund to external investors and return approximately $235 million (about 50% of the fund's $470 million AUM). The decision follows a diagnosis and recurrence of grade 4 glioblastoma (GBM). Spier reports that in 2025, the fund returned 11.3% compared to 17.9% for the S&P 500. He outlines the orderly liquidation process, shares personal reflections on his 28-year investing career, and offers a five-point framework for selecting investment stewards (skin in the game, sole focus, run as an activity rather than a business, competence/candor, and the fiduciary gene). Going forward, the fund will transition to a family office, concentrating strictly on durable compounders like Berkshire Hathaway, Nestlé, and Mastercard.
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Algorithmic conviction, macroeconomic posture, and risk appetite signals extracted from this quarterly letter with qualitative explanations.
Market Conviction
High-conviction positioning: Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Growth Outlook
Market outlook remains moderate conviction: Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Risk Appetite
Risk appetite posture is low conviction: Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Capital Deployment
Capital deployment remained balanced with selective rotation across positions. Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Forward Guidance
Forward guidance signal: Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Language Signal
Tone analysis indicates high conviction language: Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Perceived Risk
Perceived risk level is evaluated as high conviction. Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Opportunity Density
Opportunity density index indicates moderate conviction actionable entry points. Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
Time Horizon
Investment time horizon reflects a high conviction orientation. Guy Spier is winding down the Aquamarine Fund and returning outside capital due to a recurrence of glioblastoma, transitioning the remaining assets into a family office focused on ...
