Bill Ackman · William von Mueffling
what they both own
Both Bill Ackman (Pershing Square Capital) and William von Mueffling (Cantillon Capital Management) hold 4 of the same stocks per their latest 13F filings — a Jaccard overlap of 9.5% across portfolios of 11 and 35 positions. Combined position weight in shared names: 70.3% of each investor's portfolio capacity.
Shared positions, ranked by joint conviction
Joint conviction = Bill Ackman's portfolio weight + William von Mueffling's portfolio weight. A stock that both investors size heavily ranks higher than one both hold marginally. Position weight reflects each investor's most recent 13F filing (45-day SEC lag applies; filings can be 1-3 months old).
| Ticker | Ackman | Mueffling | Joint | ConvictionScore |
|---|---|---|---|---|
| BN | 17.6% | 8.7% | 26.3% | 0 |
| UBER | 15.7% | 2.6% | 18.3% | 0 |
| MSFT | 15.3% | 2.9% | 18.2% | 0 |
| GOOGL | 0.1% | 7.4% | 7.5% | 0 |
Compare individually
Data note. Position percentages are derived from each investor's most recent SEC Form 13F filing (45-day lag), filtered to disclosed long positions only. 13F filings exclude short positions, options (mostly), foreign-domiciled holdings, and positions below the reporting threshold. Joint conviction is a descriptive sum, not a recommendation. Per HoldLens compliance: this page is factual portfolio comparison, not investment advice. Always verify against the source filing before acting.