Iron Mountain (IRM) Shares Outstanding (2009 - 2026)

Iron Mountain has disclosed Shares Outstanding across 18 years of filings, most recently posting $297.5 million for Q1 2026.

• Shares Outstanding for Q1 2026 came in at $297.5 million, up 0.85% year-over-year; the trailing twelve-month figure through Mar 2026 was $297.5 million (up 0.85% YoY), and the FY2025 annual result was $295.8 million, up 0.75% from the prior year.
• Shares Outstanding came in at $297.5 million for Q1 2026 at Iron Mountain, up from $295.8 million in the prior quarter.
• In the past five years, Shares Outstanding ranged from a high of $291.6 billion in Q1 2023 to a low of $290.6 million in Q1 2022.
• The 5-year median for Shares Outstanding is $293.3 million (2024), against an average of $17.4 billion.
• Across the five-year window, Shares Outstanding surged 100256.07% in 2023 and plunged 99.9% in 2024, its largest moves.
• Iron Mountain's Shares Outstanding stood at $290.8 million in 2022, then grew by 0.45% to $292.1 million in 2023, then increased by 0.5% to $293.6 million in 2024, then climbed by 0.75% to $295.8 million in 2025, then grew by 0.57% to $297.5 million in 2026.
• The last three Shares Outstanding figures came in at $297.5 million (Q1 2026), $295.8 million (Q4 2025), and $295.5 million (Q3 2025), per Business Quant data.