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 $6.73T AUM 46.02% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return
Raymond James Financial
Raymond James Financial St Petersburg, Florida $369B AUM 28.27% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Bank of New York Mellon
Bank of New York Mellon New York $609B AUM 40.19% 1-Year Est. Return
Boston Partners
Boston Partners Boston, Massachusetts $113B AUM 38.87% 1-Year Est. Return

William Blair & Company's MPC Position: Q2 2026 in Review

William Blair & Company increased its Marathon Petroleum (MPC) stake by 4.8% in Q2 2026, buying an estimated $482K and bringing the position to 43,095 shares worth $11M. The position accounts for 0.03% of the portfolio, ranked #352.

William Blair & Company first reported a position in MPC in Q4 2013 and has held it in 50 quarters since. 1,952 funds tracked by Wall St. Rank hold MPC as of Q2 2026.

  • William Blair & Company held 43,095 shares of Marathon Petroleum worth $11M as of Q2 2026.
  • William Blair & Company bought 1,963 Marathon Petroleum shares in Q2 2026, an estimated $482K.
  • Marathon Petroleum made up 0.03% of William Blair & Company's portfolio in Q2 2026, its #352 holding.
  • William Blair & Company first reported a position in Marathon Petroleum in Q4 2013 and has held it in 50 quarters since.
  • 1,952 funds tracked by Wall St. Rank held Marathon Petroleum as of Q2 2026.

Based on William Blair & Company's 13F filing for Q2 2026, filed 11 Aug 2026.