Bill Ackman · Stephen Mandel
what they both own
Both Bill Ackman (Pershing Square Capital) and Stephen Mandel (Lone Pine Capital) hold 2 of the same stocks per their latest 13F filings — a Jaccard overlap of 6.1% across portfolios of 11 and 24 positions. Combined position weight in shared names: 21.7% of each investor's portfolio capacity.
At 6.1% Jaccard, Bill Ackman and Stephen Mandel run largely independent books — they intersect on only 2 names. Those 2 shared names carry 21.7% of combined portfolio weight, so the overlap is spread across smaller positions rather than core holdings. The name both size most heavily by joint weight is BN.
Jaccard = shared tickers ÷ all distinct tickers across both books (long positions only; 13F excludes shorts, most options, and sub-threshold stakes). Descriptive overlap measure, not investment advice.
Shared positions, ranked by joint conviction
Joint conviction = Bill Ackman's portfolio weight + Stephen Mandel'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).
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.
Frequently asked questions
How many stocks do Bill Ackman and Stephen Mandel both hold?
Both Bill Ackman (Pershing Square Capital) and Stephen Mandel (Lone Pine Capital) hold 2 of the same stocks per their latest SEC Form 13F filings — a Jaccard overlap of 6.1% across portfolios of 11 and 24 positions.
What is the biggest shared position between Bill Ackman and Stephen Mandel?
Highest joint-conviction shared position: BN. Joint conviction is the sum of each investor's portfolio weight in the same stock. The complete ranked list (top 25) is in the table below; full data sourced from each fund's latest 13F filing (45-day SEC lag applies).
What is the Jaccard overlap between Bill Ackman and Stephen Mandel?
6.1% — the Jaccard coefficient between Pershing Square Capital's and Lone Pine Capital's tracked long positions. Calculated as |A ∩ B| / |A ∪ B| over shared tickers. Higher means more portfolio convergence; 0% means no shared names.
What is "joint conviction" on HoldLens?
Joint conviction is the sum of Bill Ackman's and Stephen Mandel's respective portfolio weights in a shared stock. 21.7% is the combined weight across all shared names — a descriptive measure of how much portfolio capacity both managers concentrate in overlapping positions, not a recommendation.