Iron Mountain Stock Up 10.6% in Six Months: Will the Trend Last?

Iron Mountain (IRM) shares have risen 10.6% over the past six months, significantly outperforming its industry, fueled by strong Q2 2025 adjusted funds from operations (AFFO) of $1.24, marking a 14.8% year-over-year increase. This robust performance stems from its stable storage business, boasting a 93% retention rate, and rapid expansion in its data center segment, which grew 24% in Q2 2025 and is 96% leased with a nearly 30% growth outlook for the year. Bolstered by a strong balance sheet and a recent 10.6% dividend hike, IRM's outlook remains positive despite potential headwinds from competition and interest expenses.

Analysis

Iron Mountain (IRM) is demonstrating significant outperformance, with its stock rising 10.6% in six months against a 5.2% decline for its industry peer group. This is underpinned by a robust dual-business model. The core storage and records management segment provides a stable foundation of recurring revenue, underscored by a high customer retention rate of 93% in Q2 2025. This stability is fueling an aggressive and successful expansion into the high-growth data center market. The data center segment's revenue grew 24% year-over-year in the second quarter, with a 96% leased portfolio and a full-year growth outlook approaching 30%. Financially, this strategy translated into a second-quarter adjusted FFO per share of $1.24, a 14.8% year-over-year increase that beat consensus estimates. The company's balance sheet has strengthened considerably, with net lease-adjusted leverage falling to 5.0x, its lowest level since its 2014 REIT conversion. This financial health supports a recent 10.6% dividend hike, which appears sustainable given the projected 11.9% AFFO growth for 2025. While higher interest expenses and competitive pressures are noted as headwinds, the overall picture is one of successful strategic execution and strong financial performance.

Key Decisions for Investors

• Investors should assess IRM as a hybrid investment, where its high-retention (93%) legacy storage business provides a stable cash flow to fund the high-growth data center segment, which is the primary driver of its recent outperformance.
• Continued conviction in the stock is contingent on the data center segment meeting its ambitious near-30% revenue growth target; any deceleration in leasing or revenue could challenge the stock's recent momentum and premium.
• For income-focused investors, the 10.6% dividend increase is a strong positive signal, supported by a healthy balance sheet and strong AFFO growth, but this should be weighed against the stock's increasing correlation to the more volatile data center sector.
• Despite the strengthened balance sheet, it is prudent to monitor the impact of interest expenses and foreign currency movements, as these factors were cited as headwinds that partially offset strong operational results in the last quarter.