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Latest period

299M

YoY change

+0.5%

5Y CAGR

+0.6%

Peak year (FY2025)

298M

Shares Outstanding history chart for Iron Mountain (IRM) from 2016 to 2025

Latest: 298M

Shares Outstanding growth chart for Iron Mountain (IRM) from 2016 to 2025

Latest: +0.5%

Shares Outstanding history table for Iron Mountain (IRM) from 1996 to 2025

  • FY2025298M+0.5%
  • FY2024296M+0.8%
  • FY2023294M+0.5%
  • FY2022292M+0.5%
  • FY2021291M+0.8%
  • FY2020289M+0.3%
  • FY2019288M+0.4%
  • FY2018287M+7.4%
  • FY2017267M+7.9%
  • FY2016247M+16.6%
  • FY2015212M+7.8%
  • FY2014197M+2.3%
  • FY2013192M+10.0%
  • FY2012175M-10.8%
  • FY2011196M-3.0%
  • FY2010202M-1.1%
  • FY2009204M+0.5%
  • FY2008203M+0.6%
  • FY2007202M+0.8%
  • FY2006200M+1.2%
  • FY2005198M+0.7%
  • FY2004197M+0.8%
  • FY2003195M+0.8%
  • FY2002194M+2.9%
  • FY2001188M+5.0%
  • FY2000179M+59.3%
  • FY1999113M+10.4%
  • FY1998102M+74.8%
  • FY199758.3M+1.0%
  • FY199657.8M

Shares Outstanding values are taken from Iron Mountain's reported income statements (quarterly 10-Q and annual 10-K filings with the U.S. Securities and Exchange Commission). Each row shows the period end date and the filing date. YoY compares each figure to the same period one year earlier. Amounts are in USD as filed.

About Shares Outstanding at Iron Mountain (IRM)

According to Iron Mountain's latest reported financial statements, the company's latest reported diluted shares outstanding is 299M. Diluted weighted-average shares outstanding is the share count used to compute per-share metrics like EPS. Buybacks lower it; new issuance, stock-based compensation, and convertible securities raise it. Multiply by the stock price for market capitalization.

Headline figure above is from the reporting period ending (reported ). Chart and table below cover the full reported history back to .

In 2025, Iron Mountain (IRM) diluted shares outstanding totalled 298M – edged up 0.5% year-over-year.

Across 2020–2025 (5 years), Iron Mountain diluted shares outstanding produced a CAGR of +0.6% – sustaining 13 straight years of year-over-year growth.

298M stands as the all-time-high annual diluted shares outstanding, posted in 2025, against a low of 57.8M during 1996.

Iron Mountain Shares Outstanding by Year

Iron Mountain Shares Outstanding 2025: 298M

2025's diluted shares outstanding for Iron Mountain came in at 298M, edged up 0.5% from 2024. This figure represents the highest annual value in the available history.

Iron Mountain Shares Outstanding 2024: 296M

Iron Mountain posted diluted shares outstanding of 296M in 2024, edged up 0.8% from 2023.

Iron Mountain Shares Outstanding 2023: 294M

In 2023, Iron Mountain reported diluted shares outstanding of 294M, edged up 0.5% from 2022.

Iron Mountain Shares Outstanding 2022: 292M

Iron Mountain diluted shares outstanding in 2022 was 292M, edged up 0.5% from 2021.

Iron Mountain Shares Outstanding 2021: 291M

Iron Mountain diluted shares outstanding in 2021 was 291M.

See more financial history for Iron Mountain (IRM).

Sector peers by Shares Outstanding

Real Estate peers of Iron Mountain (IRM), ranked by their latest diluted shares outstanding

Frequently asked questions