Route One Investment Company, L.P. In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 15, 2026), Route One Investment Company, L.P. reported 18 stock positions worth $2.3 billion . Its top holding was Post (POST) at 12.8% of the portfolio, followed by Guidewire Software (GWRE, 12.1% ) and Amazon.com (AMZN, 9.4% ). Compared with Q4 2025, it opened 3 new positions, added to 7 and reduced 6. The biggest buy was a new position in MercadoLibre (MELI) and the biggest sale Essex Property Trust (ESS, shares −44% ).
Location San Francisco, CA
CIK 0001512171
Portfolio Value $2.3B (Q1 2026) Holdings 18 stocks · $2.3B Holdings quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock % Of Portfolio ▼ Shares Held Total Value Change vs Q4 2025 POST Post Holdings Inc. filed as POST HLDGS INC 2,950,568 $291.7M Reduce -5.9% GWRE Guidewire Software Inc. 1,849,364 $276.6M Add +10.7% AMZN Amazon.com Inc. 1,032,200 $215.0M Reduce -9.3% NYT New York Times Co. Class A 2,458,659 $205.9M Reduce -20.8% GOOG Alphabet Inc. Class C 689,080 $197.7M No change SCHW Schwab (charles) Corp. 1,682,243 $158.1M Reduce -8.5% UNH Unitedhealth Group Inc. 532,875 $144.2M Add +5.0% TMO Thermo Fisher Scientific Inc. 258,700 $127.2M Reduce -1.9% HLF Herbalife Ltd. 8,227,300 $121.1M Add +0.8% KRC Kilroy Realty Corp. 4,049,563 $114.2M Add +38.0% VIST Vista Energy Sab DE CV 1,216,700 $91.8M Add +18.8% MELI MercadoLibre Inc. 44,785 $77.4M New ESS Essex Property Trust Inc. 297,912 $72.1M Reduce -44.1% TBBB BBB Foods Inc. Class A 1,529,296 $54.1M Add +10.4% PCOR Procore Technologies Inc. 918,205 $52.3M No change VEEV Veeva Systems Inc. Class A 182,200 $32.0M Add +17.5% GGAL Grupo Financiero Galicia-ADR 579,350 $27.1M New BMA Banco Macro SA-ADR 332,111 $25.7M New
Options reported separately and not counted above: SPY puts ($65.0M).
Portfolio Sells Q4 2025 → Q1 2026 Portfolio Sells quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q4 2025 % Of Portfolio Change To Portfolio ▲ ESS Essex Property Trust Inc. Reduce -44.1% 3.16% −2.66 AMZN Amazon.com Inc. Reduce -9.3% 9.41% −1.55 TMO Thermo Fisher Scientific Inc. Reduce -1.9% 5.57% −0.81 SCHW Schwab (charles) Corp. Reduce -8.5% 6.92% −0.74 POST Post Holdings Inc. Reduce -5.9% 12.77% −0.19 NYT New York Times Co. Class A Reduce -20.8% 9.01% +0.02
Portfolio Buys Q4 2025 → Q1 2026 Portfolio Buys quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q4 2025 % Of Portfolio Change To Portfolio ▼ MELI MercadoLibre Inc. New 3.39% +3.39 VIST Vista Energy Sab DE CV Add +18.8% 4.02% +1.94 GGAL Grupo Financiero Galicia-ADR New 1.18% +1.18 BMA Banco Macro SA-ADR New 1.13% +1.13 HLF Herbalife Ltd. Add +0.8% 5.30% +0.91 TBBB BBB Foods Inc. Class A Add +10.4% 2.37% +0.44 KRC Kilroy Realty Corp. Add +38.0% 5.00% +0.42 VEEV Veeva Systems Inc. Class A Add +17.5% 1.40% −0.04 UNH Unitedhealth Group Inc. Add +5.0% 6.31% −0.67 GWRE Guidewire Software Inc. Add +10.7% 12.11% −1.90
Options Activity Q4 2025 → Q1 2026 Security Type Change vs Q4 2025 Underlying Shares Value ▼ IWM iShares Russell 2000 ETF put Sold out 1,200,000 $295.4Mbefore exit SPY SS SPDR S&P 500 ETF Trust-US put New 100,000 $65.0M
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
All Filings Quarter Positions 13F Reported Value Top Holdings Q2 2026 19 $2.4B POST, AMZN, GWRE, GOOG, UNH Q1 2026 18 $2.3B POST, GWRE, AMZN, NYT, GOOG Q4 2025 15 $2.4B GWRE, POST, AMZN, GOOG, NYT Q3 2025 16 $2.5B GWRE, POST, AMZN, SCHW, NYT Q2 2025 14 $2.2B GWRE, POST, AMZN, SCHW, NYT Q1 2025 13 $2.3B POST, GWRE, SCHW, AMZN, UNH Q4 2024 13 $2.5B POST, GWRE, AMZN, SCHW, UNH Q3 2024 15 $2.8B GWRE, POST, AMZN, UNH, SCHW Q2 2024 15 $2.6B POST, GWRE, AMZN, UNH, GOOG Q1 2024 16 $2.5B POST, GWRE, AMZN, UNH, CRM