AMT vs. IRM: American Tower vs. Iron Mountain Stock Comparison

November 11, 2026

How do American Tower (AMT) and Iron Mountain (IRM) stack up? This page sets them side by side across company profile, performance and risk, profitability, growth, financial strength, dividends, and valuation, with selected fundamentals also measured against each stock's industry-group peers.

Company Profile

American Tower (AMT) and Iron Mountain (IRM) both belong to the Specialized REITs industry, though AMT is classified under Telecom Tower REITs while IRM falls under Other Specialized REITs.

Both American Tower (AMT) and Iron Mountain (IRM) are REITs — read their payout ratios and P/E alongside FFO (funds from operations) rather than at face value.

Company profile comparison for American Tower (AMT) and Iron Mountain (IRM)
Profile Item	AMT	IRM
Name	American Tower Corporation	Iron Mountain Inc.
Country/Region	United States	United States
GICS Sector	Real Estate	Real Estate
GICS Industry Group	Equity Real Estate Investment Trusts (REITs)	Equity Real Estate Investment Trusts (REITs)
GICS Industry	Specialized REITs	Specialized REITs
GICS Sub-Industry	Telecom Tower REITs	Other Specialized REITs
Market Capitalization	87.55 billion USD	31.73 billion USD
Currency	USD	USD
Exchange	NYSE	NYSE
Listing Date	February 27, 1998	February 1, 1996
Security Type	REIT	REIT

Price Performance

Cumulative Growth

AMT

IRM

GSPC

American Tower (AMT) vs. Iron Mountain (IRM), with S&P 500 (GSPC) for reference: Growth of a $10,000 investment over the past five years. Adjusted for dividends and splits.

Trailing Returns

Loading price history…

Trailing total returns for American Tower (AMT) and Iron Mountain (IRM). Returns over one year are annualized.

Calendar-Year Returns

Loading price history…

Calendar-year total returns for American Tower (AMT) and Iron Mountain (IRM). Each bar is that year's total return, measured year-end to year-end.

Performance Metrics

Price performance metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Total Return (1Y)	11.16%	12.13%
Total Return (3Y, Annualized)	5.13%	28.29%
Total Return (5Y, Annualized)	-4.39%	23.46%

Risk Profile

Drawdown History

AMT

IRM

GSPC

American Tower (AMT) vs. Iron Mountain (IRM), with S&P 500 (GSPC) for reference: Drawdown from the running peak over the past five years. Each line shows the decline from its prior peak; 0% marks a new high.

Return Distribution

Loading price history…

Distribution of monthly total returns for American Tower (AMT) and Iron Mountain (IRM). Each bar is the share of months whose return fell in that 5% bucket.

Risk Metrics

Risk profile metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Volatility (1Y, Annualized)	28.50%	35.33%
Beta (5Y)	0.83	1.19
Max Drawdown (5Y)	-43.81%	-39.03%
Avg. Volume (3M)	2.79M	1.52M

Risk-Adjusted Performance

Risk-Return Positioning

AMT and IRM are plotted by 1-year volatility (risk) and 1-year return. The dashed Capital Allocation Line runs from the risk-free rate through the shared industry median.

Risk-Adjusted Metrics

Risk-adjusted metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Sharpe Ratio (1Y)	0.24	0.22
Sortino Ratio (1Y)	0.37	0.31

Profitability

ROE (TTM)

Capital efficiency shows on one side only: American Tower (AMT) earns 32.96% on shareholders’ equity, ranked against its industry; Iron Mountain (IRM) has no ROE this period.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

32.96%

AMT: 32.96%
Max: 22.74%
Q3: 10.54%
Median: 6.38%
Q1: 1.69%
Min: -10.86%

IRM

Equity Real Estate Investment Trusts (REITs) industry group

Max: 22.74%
Q3: 10.54%
Median: 6.38%
Q1: 1.69%
Min: -10.86%
IRM: --

American Tower (AMT) vs. Iron Mountain (IRM): IRM does not report ROE, so it has no value marker; AMT is benchmarked against the Equity Real Estate Investment Trusts (REITs) industry group.

Net Margin (TTM)

Neither American Tower (AMT) in Equity Real Estate Investment Trusts (REITs) nor Iron Mountain (IRM) in Equity Real Estate Investment Trusts (REITs) is well served by net margin: heavy depreciation makes net income a poor profitability proxy in their businesses, where FFO-based measures are the standard read.

Operating Margin (TTM)

Neither side reports a meaningful operating margin: for American Tower (AMT) in Equity Real Estate Investment Trusts (REITs) and Iron Mountain (IRM) in Equity Real Estate Investment Trusts (REITs), funding costs are part of the core business, so net margin and ROE are the cleaner profitability reads.

Profitability Metrics

Profitability metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
ROE (TTM)	32.96%	--
ROA (TTM)	4.94%	4.72%
Net Margin (TTM)	--	--
Operating Margin (TTM)	--	--
Gross Margin (TTM)	--	--

Growth

Revenue Growth

Iron Mountain (IRM) at 12.23% sits in the top revenue growth quartile, while American Tower (AMT) at 5.11% is closer to the peer norm — faster top-line expansion for IRM.

American Tower (AMT) vs. Iron Mountain (IRM): A comparison of their Revenue Growth across different time periods.

EPS Growth

EPS growth isn't a meaningful figure for either American Tower (AMT) in Equity Real Estate Investment Trusts (REITs) or Iron Mountain (IRM) in Equity Real Estate Investment Trusts (REITs) under our convention.

Growth Metrics

Growth metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Revenue Growth (YoY)	5.11%	12.23%
Revenue Growth (3Y CAGR)	3.34%	10.58%
EPS Growth (YoY)	--	--
EPS Growth (3Y CAGR)	--	--

Financial Strength

Current Ratio (MRQ)

Both American Tower (AMT) at 0.35 and Iron Mountain (IRM) at 0.56 run current ratio in the tighter-liquidity quartile of industry peers, leaving thinner cushions against current liabilities than typical competitors.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

0.35

Max: 4.19
Q3: 2.11
Median: 1.31
Q1: 0.62
AMT: 0.35
Min: 0.06

IRM

Equity Real Estate Investment Trusts (REITs) industry group

0.56

Max: 4.19
Q3: 2.11
Median: 1.31
Q1: 0.62
IRM: 0.56
Min: 0.06

American Tower (AMT) vs. Iron Mountain (IRM): A comparison of their current ratio against the Equity Real Estate Investment Trusts (REITs) industry group benchmark.

Debt / Equity (MRQ)

Only one side’s leverage can be read here: American Tower (AMT) carries debt-to-equity ratio of 4.64 against its industry range, while Iron Mountain (IRM) reports no figure this period.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

4.64

AMT: 4.64
Max: 2.72
Q3: 1.59
Median: 0.99
Q1: 0.72
Min: 0.20

IRM

Equity Real Estate Investment Trusts (REITs) industry group

Max: 2.72
Q3: 1.59
Median: 0.99
Q1: 0.72
Min: 0.20
IRM: --

American Tower (AMT) vs. Iron Mountain (IRM): IRM does not report debt-to-equity ratio, so it has no value marker; AMT is benchmarked against the Equity Real Estate Investment Trusts (REITs) industry group.

Financial Strength Metrics

Financial strength metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Current Ratio (MRQ)	0.35	0.56
Debt / Equity (MRQ)	4.64	--
Net Debt / EBITDA	6.14	7.69

Dividends

Dividend Yield (TTM)

Both American Tower (AMT) at 3.64% and Iron Mountain (IRM) at 3.28% pay solid, industry-typical yields, sitting squarely within their peers’ usual range.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

3.64%

Max: 8.62%
Q3: 5.95%
Median: 4.34%
AMT: 3.64%
Q1: 3.26%
Min: 0.00%

IRM

Equity Real Estate Investment Trusts (REITs) industry group

3.28%

Max: 8.62%
Q3: 5.95%
Median: 4.34%
IRM: 3.28%
Q1: 3.26%
Min: 0.00%

American Tower (AMT) vs. Iron Mountain (IRM): A comparison of their dividend yield against the Equity Real Estate Investment Trusts (REITs) industry group benchmark.

Dividend Payout Ratio (TTM)

An earnings-based payout ratio fits neither American Tower (AMT) in Equity Real Estate Investment Trusts (REITs) nor Iron Mountain (IRM) in Equity Real Estate Investment Trusts (REITs): their distributions are mandated and conventionally measured against FFO, so the accounting-earnings ratio overstates both.

Dividend Metrics

Dividend metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
Dividend Yield (TTM)	3.64%	3.28%
Dividend Payout Ratio (TTM)	--	--

Valuation

P/E Ratio (TTM)

P/E ratio is not a meaningful valuation yardstick for either American Tower (AMT) in Equity Real Estate Investment Trusts (REITs) or Iron Mountain (IRM) in Equity Real Estate Investment Trusts (REITs): depreciation suppresses reported earnings in their businesses, and price-to-FFO is the conventional yardstick instead.

P/S Ratio (TTM)

On P/S ratio, both American Tower (AMT) at 7.95 and Iron Mountain (IRM) at 4.07 are priced roughly in line with their industries — neither looks cheap nor rich on a sales basis.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

7.95

Max: 14.47
Q3: 8.02
AMT: 7.95
Median: 5.98
Q1: 3.27
Min: 0.43

IRM

Equity Real Estate Investment Trusts (REITs) industry group

4.07

Max: 14.47
Q3: 8.02
Median: 5.98
IRM: 4.07
Q1: 3.27
Min: 0.43

American Tower (AMT) vs. Iron Mountain (IRM): A comparison of their P/S ratio against the Equity Real Estate Investment Trusts (REITs) industry group benchmark.

P/B Ratio (MRQ)

Iron Mountain (IRM) reports a negative P/B ratio of -22.85, meaning negative book equity — the multiple itself is not meaningful for valuation. Meanwhile American Tower (AMT) reports 24.92, ranking against industry peers normally.

AMT

Equity Real Estate Investment Trusts (REITs) industry group

24.92

AMT: 24.92
Max: 4.06
Q3: 2.53
Median: 1.64
Q1: 1.06
Min: 0.21

IRM

Equity Real Estate Investment Trusts (REITs) industry group

-22.85

Max: 4.06
Q3: 2.53
Median: 1.64
Q1: 1.06
Min: 0.21
IRM: -22.85

American Tower (AMT) vs. Iron Mountain (IRM): A comparison of their P/B ratio against the Equity Real Estate Investment Trusts (REITs) industry group benchmark.

Valuation Metrics

Valuation metrics for American Tower (AMT) and Iron Mountain (IRM)
Metric	AMT	IRM
P/E Ratio (TTM)	--	--
P/S Ratio (TTM)	7.95	4.07
P/B Ratio (MRQ)	24.92	-22.85
Free Cash Flow Yield (TTM)	--	--