William John Sempolinski’s Iron Mountain IRM Stock Holding History

William John Sempolinski’s Portfolio IRM Stock Details IRM Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q3	–	Sell	-1,900	Closed	-$240K	–	109
2026 Q2	$240K	Buy	+1,900	New	+$233K	0.1%	99

Other funds holding IRM

BlackRock New York $6.79T AUM 37.06% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.21T AUM

Vanguard Capital Management Malvern, Pennsylvania $4.76T AUM

State Street Boston, Massachusetts $3.44T AUM 36.12% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.92T AUM 36.1% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return

Morgan Stanley New York $1.96T AUM 27.49% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $551B AUM 33.95% 1-Year Est. Return

Invesco Atlanta, Georgia $1.27T AUM 50.62% 1-Year Est. Return

Principal Financial Group Des Moines, Iowa $195B AUM 21.17% 1-Year Est. Return

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

William John Sempolinski sold out of Iron Mountain (IRM) in Q3 2026, closing a stake of 1,900 shares — an estimated $240K sold.

William John Sempolinski first reported a position in IRM in Q2 2026 and held it in 1 quarter. The position peaked at $240K in Q2 2026. 1,000 funds tracked by Wall St. Rank hold IRM as of Q3 2026.

William John Sempolinski reported no remaining Iron Mountain position as of Q3 2026 after selling out during the quarter.
William John Sempolinski sold 1,900 Iron Mountain shares in Q3 2026, an estimated $240K.
William John Sempolinski first reported a position in Iron Mountain in Q2 2026 and held it in 1 quarter.
William John Sempolinski's Iron Mountain position peaked at $240K in Q2 2026.
1,000 funds tracked by Wall St. Rank held Iron Mountain as of Q3 2026.

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