Sifting through countless of stocks in the Retail REITs industry can be tedious, and sometimes two stocks are just too similar to judge which is the better investment. If you’re on the fence about investing in Realty Income Corporation or Iron Mountain Incorporated because you’re not sure how they measure up, it’s important to compare them on a few factors before making your decision.

Read on to learn how Realty Income Corporation and Iron Mountain Incorporated compare based on key financial metrics to determine which better meets your investment needs.

About Realty Income Corporation and Iron Mountain Incorporated

Realty Income Corporation, an S&P 500 company, is real estate partner to the world's leading companies. Founded in 1969, we serve our clients as a full-service real estate capital provider. As of June 30, 2026, we have a portfolio of over 15,500 properties in all 50 U.S. states, the U.K., and eight other countries in Europe. We are known as "The Monthly Dividend Company" and have a mission to invest in people and places to deliver dependable monthly dividends that increase over time. Since our founding, we have declared 674 consecutive monthly dividends and are a member of the S&P 500 Dividend Aristocrats index for having increased our dividend for over 31 consecutive years. Realty Income Corporation was founded in 1969 and was incorporated in Maryland.

Iron Mountain Incorporated is trusted by more than 240,000 customers in 61 countries, including approximately 95% of the Fortune 1000, to help unlock value and intelligence from their assets through services that transcend the physical and digital worlds. Our broad range of solutions address their information management, digital transformation, information security, data center and asset lifecycle management needs. Iron Mountain Incorporated is based in Portsmouth, New Hampshire. Iron Mountain Incorporated was founded in 1951 and is incorporated in Delaware and is based in Portsmouth, New Hampshire.

Latest Retail REITs and Realty Income Corporation, Iron Mountain Incorporated Stock News

As of September 4, 2026, Realty Income Corporation had a $57.8 billion market capitalization, compared to the Retail REITs median of $4.7 million. Realty Income Corporation’s stock is NA in 2026, NA in the previous five trading days and up 5.1% in the past year.

Currently, Realty Income Corporation’s price-earnings ratio is 44.8. Realty Income Corporation’s trailing 12-month revenue is $6.1 billion with a 20.9% net profit margin. Year-over-year quarterly sales growth most recently was 9.6%. Analysts expect adjusted earnings to reach $1.666 per share for the current fiscal year. Realty Income Corporation currently has a 5.3% dividend yield.

Currently, Iron Mountain Incorporated’s price-earnings ratio is 83.3. Iron Mountain Incorporated’s trailing 12-month revenue is $7.6 billion with a 5.5% net profit margin. Year-over-year quarterly sales growth most recently was 18.5%. Analysts expect adjusted earnings to reach $2.481 per share for the current fiscal year. Iron Mountain Incorporated currently has a 3.0% dividend yield.

How We Compare Realty Income Corporation and Iron Mountain Incorporated Stock Grades

Stock evaluation requires access to huge amounts of data and the knowledge and time to sift through it all, make sense of financial ratios, read income statements and analyze recent stock movements. AAII created A+ Investor, a robust data suite that condenses data research in an actionable and customizable way suitable for investors of all knowledge levels, to help investors streamline and work through such data.

AAII’s proprietary stock grades come with A+ Investor. These offer intuitive A‐F grades for each of five key investing factors: value, growth, momentum, earnings estimate revisions and quality. Here, we’ll take a closer look at Realty Income Corporation and Iron Mountain Incorporated’s stock grades to see how they measure up against one another.

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Realty Income Corporation and Iron Mountain Incorporated Stock Value Grades

Company	Ticker	Value
Realty Income Corporation	O	D
Iron Mountain Incorporated	IRM	F

Successful stock investing involves buying low and selling high, so stock valuation is an important consideration for stock selection.

Buying stocks that are going to go up typically means buying stocks that are undervalued in the first place, although momentum investors may argue that point.

AAII’s A+ Investor Value Grade derives from a stock’s value score. The Value Score is the percentile rank of the average of the percentile ranks of the price-to-sales ratio, price-earnings ratio, enterprise-value-to-EBITDA (EV/EBITDA) ratio, shareholder yield, price-to-book-value ratio and price-to-free-cash-flow ratio. The score is variable, meaning it can consider all six ratios or, should any of the six ratios not be valid, the remaining ratios that are valid. To be assigned a Value Score, stocks must have a valid (non-null) ratio and corresponding ranking for at least two of the six valuation ratios.

Stocks with a Value Score from 81 to 100 are considered deep value, those with a score between 61 and 80 are a good value and so on.

Realty Income Corporation has a Value Score of 25, which is Expensive. Iron Mountain Incorporated has a Value Score of 19, which is Ultra Expensive.

The Value Stock Winner: No Clear Winner

Neither Realty Income Corporation or Iron Mountain Incorporated has a high enough value grade to be considered a “winner.” Investors who are considering these companies should do additional due diligence and research to see if either could be a good addition to their portfolio. It’s important to look at a wide range of financial metrics in order to determine if Realty Income Corporation or Iron Mountain Incorporated is the better investment when it comes to value.

Realty Income Corporation and Iron Mountain Incorporated’s Momentum Grades

Company	Ticker	Momentum
Realty Income Corporation	O	C
Iron Mountain Incorporated	IRM	C

Momentum grades help to uncover stocks experiencing anomalously high rates of return; research finds that stocks with high relative levels of momentum tend to outperform, whereas those with low levels of momentum tend to continue underperforming. Momentum is based on the price change of a stock over a specified period relative to all other stocks.

Typically, AAII looks at the weighted relative strength over the trailing four quarters. The weighted four-quarter relative strength rank is the relative price change for each of the past four quarters. The most recent quarterly price change is given a weight of 40% and each of the three previous quarters are given a weighting of 20%.

Realty Income Corporation has a Momentum Score of 42, which is Average. Iron Mountain Incorporated has a Momentum Score of 54, which is Average.

The Momentum Stock Winner: No Clear Winner

Neither Realty Income Corporation or Iron Mountain Incorporated has a strong enough Momentum Grade to be considered a “winner.” Investors considering these companies should do additional due diligence and research to see if either could be a good addition to their portfolios. It’s important to look at a wide range of financial metrics in order to determine if Realty Income Corporation or Iron Mountain Incorporated is the better investment when it comes to momentum.

Realty Income Corporation and Iron Mountain Incorporated’s Estimate Revisions Grades

Company	Ticker	Earnings Estimate
Realty Income Corporation	O	D
Iron Mountain Incorporated	IRM	C

Earnings estimate revisions scores consider the magnitude of a company’s earnings surprise in its last two reported fiscal quarters. Often, positive surprises beget further positive surprises‐or at least continued sales growth (the exact opposite is generally true, too).

Estimate revisions offer an indication of what analysts are thinking about the short-term prospects of a firm. Estimate revisions are based on the statistical significance of a firm’s last two quarterly earnings surprises and the percentage change in its consensus estimate for the current fiscal year over the past month and past three months.

Realty Income Corporation has a Earnings Estimate Score of 40, which is Negative. Iron Mountain Incorporated has a Earnings Estimate Score of 55, which is Neutral.

The Earnings Estimate Revisions Stock Winner: No Clear Winner

Neither Realty Income Corporation or Iron Mountain Incorporated has an Earnings Estimate Revisions Grade that could be considered a “winner.” Investors considering these companies should do additional due diligence and research to see if either could be a good addition to their portfolios. It’s important to look at a wide range of financial metrics in order to determine if Realty Income Corporation or Iron Mountain Incorporated is the better investment when it comes to estimate revisions.

Other Realty Income Corporation and Iron Mountain Incorporated Grades

In addition to Momentum, Value and Estimate Revisions, A+ Investor also provides grades for Growth and Quality.

Growth investing builds on the idea that stocks of companies exhibiting strong, consistent and prolonged growth outperform those of slower-growth companies. AAII measures growth through consistency of annual sales growth, five-year sales growth rankings adjusted for extreme levels, and consistency of positive annual cash from operations.

AAII’s A+ Investor Quality Grade comes from the ranking of key metrics. Specifically, the quality grade is the percentile rank of the composite of return on assets (ROA), return on invested capital (ROIC), gross profit relative to assets, buyback yield, change in total liabilities to assets, accruals, Z double prime bankruptcy risk (Z) score and F-Score.

These 2 key factors, when combined with the above, provide a holistic view into a particular stock. Further, by joining A+ Investor you can see whether Realty Income Corporation and Iron Mountain Incorporated pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, Realty Income Corporation or Iron Mountain Incorporated Stock?

Overall, Realty Income Corporation stock has a Value Score of 25, Momentum Score of 42 and Estimate Revisions Score of 40.

Iron Mountain Incorporated stock has a Value Score of 19, Momentum Score of 54 and Estimate Revisions Score of 55.

Comparing Realty Income Corporation and Iron Mountain Incorporated’s grades, scores and metrics can act as a solid basis to determine whether they may be a good investment or not. You’ll also want to look at your portfolio’s asset allocation as well as your risk tolerance and financial goals to see if either of these stocks would make a good fit for you. AAII can help you figure out which investments align with your individual needs and preferences.

Investors are encouraged to do their own due diligence and research. In this way, individuals can effectively become managers of their own assets‐without having to rely on others for financial independence. You can count on AAII for timeless articles on financial planning and stock-picking, unbiased research and actionable analysis.

A+ Investor adds to our qualitative teaching with a powerful data suite to help you whittle down investment choices to find stocks, exchange-traded funds (ETFs) or mutual funds that meet your needs.

AAII Disclaimer

We make no representations or warranties that any investor will, or is likely to, achieve profits similar to those shown, because past, hypothetical or simulated performance is not necessarily indicative of future results. Before making an investment decision, you should consider your circumstances and whether the information on our content is applicable to your situation. This information was prepared in good faith, and we accept no liability for any errors or omissions. The full disclaimer can be read here.