Guy Spier’s Core Natural Resources Inc (CNR) position
Reported position history, portfolio importance and verified filing changes from public SEC disclosures.
At a glance
The full verified relationship, including prior ownership episodes and exits where supported.
Aquamarine Capital first reported Core Natural Resources Inc in Q1 2025. The latest verified relationship event shows that Aquamarine Capital sold the entire position in Q4 2025, and the stock is no longer reported in the latest verified portfolio.
Position over time
See the same verified relationship through reported shares, portfolio weight or reported value.
Gaps indicate periods that cannot be safely connected or where a verified corporate action changes the raw share scale. Stock price, when available, is market context and not a transaction price.
What changed
Latest filing plus the most meaningful reported changes. Unchanged quarters are collapsed by default.
Filing context
Quarter-end price $83.52 · Estimated holding basis $77.09
Filing context
Quarter-end price $69.74 · Estimated holding basis $77.09
Filing context
Quarter-end price $77.09 · Estimated holding basis $77.09
2 unchanged quarters are collapsed by default.
How important was Core Natural Resources Inc in Aquamarine Capital’s reported portfolio?
Relative importance is measured only within the verified primary non-option reported portfolio for each quarter.
Who else owns Core Natural Resources Inc?
Also reported by 2 other tracked investors in their latest verified filings.
SEC filing evidence
Market context and filing-derived values are kept separate from actual transaction prices, which 13F filings do not disclose.
Market context only; not an investor transaction price.
This tracker follows the current Aquamarine Zurich AG Form 13F filer and bridges its verified history to the former Aquamarine Capital Management LLC filer. It does not represent Guy Spier’s personal brokerage account or the fund’s complete global portfolio.