William Blair & Company
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William Blair & Company’s Iron Mountain IRM Stock Holding History

William Blair & Company’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
2017
Q1 		– Sell
-100
Closed -$3K – 1483
2016
Q4 		$3K Buy
+100
New +$3.32K ﹤0.01% 1390

Other funds holding IRM

BlackRock
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Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
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
Cohen & Steers
Cohen & Steers New York $63.2B AUM 17.15% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return
Principal Financial Group
Principal Financial Group Des Moines, Iowa $204B AUM 27.99% 1-Year Est. Return

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

William Blair & Company reduced its Iron Mountain (IRM) stake by 0.39% in Q2 2026, selling an estimated $107K and leaving 224,376 shares worth $28.3M. The position accounts for 0.07% of the portfolio, ranked #206.

William Blair & Company first reported a position in IRM in Q2 2013 and has held it in 53 quarters since. The position peaked at $39.7M in Q3 2024. 1,171 funds tracked by Wall St. Rank hold IRM as of Q2 2026.

  • William Blair & Company held 224,376 shares of Iron Mountain worth $28.3M as of Q2 2026.
  • William Blair & Company sold 873 Iron Mountain shares in Q2 2026, an estimated $107K.
  • Iron Mountain made up 0.07% of William Blair & Company's portfolio in Q2 2026, its #206 holding.
  • William Blair & Company first reported a position in Iron Mountain in Q2 2013 and has held it in 53 quarters since.
  • William Blair & Company's Iron Mountain position peaked at $39.7M in Q3 2024.
  • 1,171 funds tracked by Wall St. Rank held Iron Mountain as of Q2 2026.

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