20% of Bill Ackman's Personal Portfolio Is Invested in This 1 Stock. Should You Follow Suit?

Pershing Square founder Bill Ackman accumulated a large Uber position in Q1 2025 (trimming ~1% in Q3) and currently allocates roughly 19% of the fund to the stock. Uber reported nearly $38 billion in revenue in the first nine months of 2025 (+18% YoY), with mobility +18% and delivery +24% (these segments represent ~90% of revenue); operating cost growth was limited to 13% and net income rose to about $9.8 billion (vs. $3.0 billion prior year), aided by a one-time $4.3 billion tax benefit. The stock is up ~40% over the last year and trades at a trailing P/E ~11, forward P/E ~13 (one-year forward P/E ~20), positioning it as a potentially undervalued, growth-oriented holding given scale in mobility/delivery and upside from autonomous-driving initiatives.

Analysis

Market structure: Rapid scale in on-demand mobility and delivery increases bargaining leverage with drivers, restaurants and advertisers—winners include high-margin ad partners, logistics software suppliers and autonomous-vehicle component vendors; legacy taxi operators and regional delivery aggregators are the structural losers as unit economics centralize. Pricing power will be tested regionally: expect continued mix-shift to higher-margin platform revenue (ads, subscriptions) in urban cores while lower-density markets keep promotional pricing alive, compressing cross-market margins by a few hundred basis points.

Risk assessment: Key tail risks are regulatory (worker classification, local fare caps), AV execution failure, and earnings quality volatility from non-recurring tax or accounting items; any adverse regulatory ruling could knock 20–40% off consensus free cash flow over 12 months. Time-profile: expect headline-driven stock moves in days around regulatory/earnings events, margin and volume normalization over quarters, and AV upside/losses realized over multi-year horizons; hidden dependencies include driver supply elasticity and fuel/insurance cost shocks.

Trade implications: Constructive directional exposure but hedge execution risk: favor concentrated equity exposure sized 1–3% of portfolio with a protective collar or put spread; exploit relative value by pairing long platform leader with short regional/smaller competitor to isolate scale benefits. Options: use 9–12 month call spreads (25–35% OTM) to express asymmetric upside and finance with near-term covered-call sales; trim on 20–30% realized upside or if forward multiples exceed your 18–22x fair band.

Key Decisions for Investors

• Establish a 2–3% long position in UBER (equity) for a 12–18 month horizon, size to risk budget; implement a hard stop-loss at -15% and plan to trim 50% of position on +25–30% realized gain.
• Implement a relative-value pair: long UBER 1% vs short LYFT 0.5% (dollar-neutral) to capture scale and margin dispersion over 6–12 months; close if LYFT outperforms UBER by >15% or if UBER reports >200bps QoQ margin deterioration.
• Buy a 9–12 month UBER call spread 25–35% OTM sized to 0.5–1% notional, financed by selling 1–3 month covered calls (rolling monthly) to monetize near-term premium; target asymmetric 2:1 payoff and exit if implied vol collapses >40% or spread hits 60% of max value.
• If regulatory signals (worker classification rulings or material local fare caps) appear within the next 60 days, reduce UBER exposure by 50% and redeploy into logistics software suppliers and AV component names that benefit from platform outsourcing (monitor filings and 10-Q notes for red flags).