IRM Iron Mountain Incorporated

Ownership history in COHEN & STEERS, INC.  ·  28 quarters on record

AI Ownership Summary

COHEN & STEERS, INC. reported Iron Mountain Incorporated (IRM) in 28 quarterly 13F filings from 2023 Q4 through 2025 Q4. Peak portfolio weight reached 4.33% in 2024 Q2. The latest visible filing shows IRM at 2.83% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings. Older history is available after unlock; the visible window still shows the most recent pattern.

What this IRM ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was COHEN & STEERS, INC.'s position in Iron Mountain Incorporated, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2025 Q4

IRM was reported at 2.83% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
4.33% in 2024 Q2

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2023 Q4 to 2025 Q4

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

How COHEN & STEERS, INC. held IRM — position size vs. price
% of Fund (quarterly)    IRM price (quarter-end, indexed to 100)
📋 Quarterly Holdings History 9 quarters  
Quarter Action Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2025 Q4 ADDED 18,903,716 +3,155,034 +20.0% 2.83% $1.57B 2026-02-14 (Est.) $108.94
2025 Q3 ADDED 15,748,682 +1,980,051 +14.4% 2.90% $1.61B 2025-11-14 $89.69
2025 Q2 ADDED 13,768,631 +286,729 +2.1% 2.59% $1.41B 2025-08-14 $88.99
2025 Q1 REDUCED 13,481,902 -1,425,944 -9.6% 2.14% $1.16B 2025-05-15 $96.13
2024 Q4 REDUCED 14,907,846 -2,818,166 -15.9% 2.97% $1.57B 2025-02-13 $91.19
2024 Q3 REDUCED 17,726,012 -5,325,004 -23.1% 3.75% $2.11B 2024-11-14 $107.61
2024 Q2 REDUCED 23,051,016 -604,022 -2.6% 4.33% $2.07B 2024-08-13 $102.01
2024 Q1 ADDED 23,655,038 +1,179,424 +5.2% 3.97% $1.90B 2024-05-15 $77.27
2023 Q4 ADDED 22,475,614 +15,035,937 +202.1% 3.18% $1.57B 2024-02-14 $62.88
19 older quarters hidden  —  Sign in free or upgrade to Premium to see full history

FAQ About COHEN & STEERS, INC. and IRM

These are the practical questions this page is built to answer before you even open the full history table.

How long has COHEN & STEERS, INC. reported owning IRM?

COHEN & STEERS, INC. reported IRM across 9 quarterly 13F filings, from 2023 Q4 through 2025 Q4.

What was the largest reported IRM position in COHEN & STEERS, INC.'s portfolio?

The largest reported portfolio weight for IRM was 4.33% in 2024 Q2.

What is the latest reported IRM position on this page?

The most recent filing on this page is 2025 Q4, when COHEN & STEERS, INC. reported 18,903,716 shares, equal to 2.83% of portfolio, with an estimated market value of $1.57B.

What does the chart on this IRM ownership page compare?

The chart compares COHEN & STEERS, INC.'s quarterly IRM portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

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