William Blair & Company
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William Blair & Company’s Marathon Petroleum MPC Stock Holding History

William Blair & Company’s Portfolio MPC Stock Details MPC Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2017
Q2 		– Sell
-1,000
Closed -$51K – 1652
2017
Q1 		$51K Buy
+1,000
New +$49.8K ﹤0.01% 1336

Other funds holding MPC

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return
Raymond James Financial
Raymond James Financial St Petersburg, Florida $324B AUM 22.36% 1-Year Est. Return
Boston Partners
Boston Partners Boston, Massachusetts $95.5B AUM 28.4% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

William Blair & Company's MPC Position: Q1 2026 in Review

William Blair & Company reduced its Marathon Petroleum (MPC) stake by 24% in Q1 2026, selling an estimated $2.67M and leaving 41,132 shares worth $10M. The position accounts for 0.03% of the portfolio, ranked #350.

William Blair & Company first reported a position in MPC in Q4 2013 and has held it in 49 quarters since. The position peaked at $10.5M in Q1 2024. 1,885 funds tracked by Wall St. Rank hold MPC as of Q1 2026.

  • William Blair & Company held 41,132 shares of Marathon Petroleum worth $10M as of Q1 2026.
  • William Blair & Company sold 13,217 Marathon Petroleum shares in Q1 2026, an estimated $2.67M.
  • Marathon Petroleum made up 0.03% of William Blair & Company's portfolio in Q1 2026, its #350 holding.
  • William Blair & Company first reported a position in Marathon Petroleum in Q4 2013 and has held it in 49 quarters since.
  • William Blair & Company's Marathon Petroleum position peaked at $10.5M in Q1 2024.
  • 1,885 funds tracked by Wall St. Rank held Marathon Petroleum as of Q1 2026.

Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.