William John Sempolinski
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William John Sempolinski’s MPLX MPLX Stock Holding History

William John Sempolinski’s Portfolio MPLX Stock Details MPLX Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q3 		$299K Hold
5,301
– – 0.12% 89
2026
Q2 		$299K Sell
5,301
-238
-4% -$13.3K 0.12% 91
2026
Q1 		$316K Buy
5,539
+700
+14% +$39.7K 0.16% 74
2025
Q4 		$258K Buy
+4,839
New +$252K 0.13% 74

Other funds holding MPLX

ALPS Advisors
ALPS Advisors Denver, Colorado $21.8B AUM 17.58% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.27T AUM 50.62% 1-Year Est. Return
Tortoise Capital Advisors
Tortoise Capital Advisors Overland Park, Kansas $9.47B AUM 23.61% 1-Year Est. Return
Kayne Anderson Capital Advisors
Kayne Anderson Capital Advisors Los Angeles, California $5.47B AUM 13.78% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.96T AUM 27.49% 1-Year Est. Return
Energy Income Partners
Energy Income Partners Westport, Connecticut $6.26B AUM 9.12% 1-Year Est. Return
Chickasaw Capital Management
Chickasaw Capital Management Memphis, Tennessee $2.79B AUM 24.88% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $765B AUM 28.39% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return
CIBC Bancorp USA
CIBC Bancorp USA Chicago, Illinois $79.9B AUM

William John Sempolinski's MPLX Position: Q3 2026 in Review

William John Sempolinski held its MPLX (MPLX) position steady in Q3 2026 at 5,301 shares worth $299K. The position accounts for 0.12% of the portfolio, ranked #89.

William John Sempolinski first reported a position in MPLX in Q4 2025 and has held it in 4 quarters since. The position peaked at $316K in Q1 2026. 547 funds tracked by Wall St. Rank hold MPLX as of Q3 2026.

  • William John Sempolinski held 5,301 shares of MPLX worth $299K as of Q3 2026.
  • William John Sempolinski left its MPLX share count unchanged in Q3 2026.
  • MPLX made up 0.12% of William John Sempolinski's portfolio in Q3 2026, its #89 holding.
  • William John Sempolinski first reported a position in MPLX in Q4 2025 and has held it in 4 quarters since.
  • William John Sempolinski's MPLX position peaked at $316K in Q1 2026.
  • 547 funds tracked by Wall St. Rank held MPLX as of Q3 2026.

Based on William John Sempolinski's 13F filing for Q3 2026, filed 20 Oct 2026.