--- title: "A short seller says Iron Mountain's data center bet barely covers its interest bill. The stock rose." description: "JCapital Research shorted Iron Mountain on October 28, arguing 81% of capex buys 13% of revenue at 1.7x interest cover. The filings agree with the arithmetic; the stock rose anyway." publisher: "The Inference" section: "Data Center" published: 2026-10-30T15:40:32.179Z modified: 2026-10-30T15:40:32.179Z canonical: https://theinference.org/article/a-short-seller-says-iron-mountain-s-data-center-bet-barely-covers-its-interest-bill-the-stock-rose language: en keywords: "Iron Mountain, Short Sellers, Data Centers, REITs, Debt" --- # A short seller says Iron Mountain's data center bet barely covers its interest bill. The stock rose. > JCapital Research shorted Iron Mountain on October 28, arguing 81% of capex buys 13% of revenue at 1.7x interest cover. The filings agree with the arithmetic; the stock rose anyway. ## The charge: 81% of the capex, 13% of the revenue JCapital Research, a forensic short shop with prior fraud-adjacent calls, published its short on [Iron Mountain](https://theinference.org/markets/companies/iron-mountain) (IRM), the records-storage REIT turned data-center landlord, on October 28, 2026, under the [title "Data Centers don't justify the optimism"](https://jcapitalresearch.substack.com/p/iron-mountain-inc-irm) [1][2]. Its public section runs on arithmetic: about 81% of total capital spending was flowing into data centers as of the second quarter, while data centers bring in only about 13% of revenue [2]. By the report's count, the company holds roughly $17.3 billion in loans against $205 million of cash, borrows at an average 5.6%, and covered its interest bill 1.7 times last quarter, with net interest expense up from $488 million in 2022 to $829 million in 2025 [2]. JCapital also suspects Iron Mountain low-balls data center maintenance costs and depreciation, inputs that flatter adjusted funds from operations, the REIT cash measure behind the dividend [2]. The full report sits behind a paywall [2]. ## The tape's first answer was to buy The short was announced on October 28 [1]. The stock closed that session up 0.29% at $115.67 [3], rose to about $118.4 the next day [4][5], and held near $116 at midday on October 30, down about 2%, while the Nasdaq 100 ETF (QQQ) dropped 2.8% [5][6]. [Short interest stood at 2.44% of float on October 15](https://www.marketbeat.com/stocks/NYSE/IRM/short-interest/), before the report, at 5.1 days to cover [6]. No gap down, no borrow squeeze so far: the market has either not priced the thesis or has priced it and disagrees. ## The filings concede the arithmetic Checked against [Iron Mountain's own filings](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001020569), the short's numbers hold. Capex exceeded operating cash flow in all ten quarters from the first quarter of 2024 through the second quarter of 2026, and total debt climbed from $15.2 billion to $19.6 billion over the same stretch [7]. A REIT must pay out most of its taxable income as dividends, which is why that gap gets debt-funded [2]. The 1.7x interest cover matches too: second-quarter operating income of $387 million against $225 million of interest expense [5]. None of that is in dispute. The dispute is whether growth capex that lifted revenue 18.5% last quarter compounds into returns above 5.6% money, or stacks obligations onto a paper-storage business [2][4]. *Chart: **Capex outran operating cash flow in all ten quarters** Line chart of quarterly capital expenditure versus operating cash flow for Iron Mountain across ten quarters, with capex above cash flow in every quarter shown.* *Capex outran operating cash flow in all ten quarters [7]* *Chart: **Debt up $4.4 billion in ten quarters while cash stayed near $200 million** Line chart of Iron Mountain total debt rising from 15.2 to 19.6 billion dollars across ten quarters while cash held near 200 million dollars.* *Debt up $4.4 billion in ten quarters while cash stayed near $200 million [7]* ## The bull ledger The bulls bring records. Second-quarter revenue hit $2.03 billion, up 18.5%; AFFO rose 17% to $433 million, or $1.44 a share, against a declared quarterly dividend of $0.864 [4]. The data center, digital and asset lifecycle management businesses grew more than 50% year over year, leasing reached [110 megawatts year to date](https://theinference.org/article/iron-mountain-s-survey-says-86-of-organizations-saw-ai-projects-stall-it-signed-110-megawatts), and management raised full-year guidance to $7.94 to $8.01 billion of revenue [4]. The company pegs net lease adjusted leverage at 4.8x, its lowest since 2014 [5]. Wall Street rates the stock eight Buys, no holds, no sells, with 12-month targets of $132 to $155 [5]. A dividend newsletter had called the pullback a buy six days before the short arrived [8]. ## The last short seller's scoreboard This is Iron Mountain's second forensic fight inside a year. On November 19, 2025 Gotham City Research [published a short](https://www.gothamcityresearch.com/post/the-dark-side-of-iron-mountain-from-a-melting-ice-cube-to-a-house-on-fire) alleging adjusted EBITDA overstated 25% to 35%, true leverage of 9x against a reported 5x, and dividends uncovered by cash flow for twelve years, valuing shares at $23 to $41 [9]. The stock bottomed at $77.77, then rallied to $129.49 by August 14, 2026, while short interest thinned from 3.8% of float in December to 2.44% [5][6]. Eleven months on, shares near $116 trade at almost three times Gotham's ceiling price [5][9]. That call was priced and, so far, rejected. *Chart: **The stock trades near three times the last short seller's ceiling** Bar chart of published price calls on Iron Mountain: Gotham City Research's $23 to $41 valuation from November 2025, the $115.67 close before the JCapital report, and Wall Street's $132 to $155 targets.* *Published share-price calls for Iron Mountain in US dollars: Gotham City Research's November 2025 valuation range, the October 28 close before the JCapital report, and Wall Street's 12-month target range. [5][9]* ## The verdict is scheduled [Third-quarter results arrive November 5](https://www.stocktitan.net/news/IRM/) before the open, with consensus at $0.61 of earnings on $1.99 billion of revenue [4][5]. Three tells decide whether JCapital's call sticks: whether data center depreciation and maintenance disclosures answer the low-balling charge, whether borrow costs and options skew reprice, the move that typically comes first in episodes like this [1], and whether capex keeps outrunning cash generation [7]. Iron Mountain's newest notes pay 6.25%, against the 15% [CoreWeave](https://theinference.org/markets/companies/coreweave) agreed to pay on its debt, [as reported here on October 17](https://theinference.org/article/ai-debt-now-has-two-prices-15-for-coreweave-6-25-for-iron-mountain); lenders have already ranked the data-center borrowers [4][10]. The arithmetic is not in dispute. What the arithmetic means is the whole fight. ## Takeaway JCapital's arithmetic on Iron Mountain checks out against the filings, but the stock has ignored the short so far; November 5 results are the test. ## Sources 1. [Newsquawk, JCapital Research announces short on Iron Mountain (IRM), 28 October 2026](https://www.newsquawk.com/headlines/jcapital-research-announces-short-on-iron-mountain-irm) 2. [J Capital Research (The Equity Dispatch), Iron Mountain Inc (IRM): Data Centers don't justify the optimism, 28 October 2026](https://jcapitalresearch.substack.com/p/iron-mountain-inc-irm) 3. [Google search snapshot quoting Iron Mountain Investor Relations overview, IRM close of $115.67 on 28 October 2026](https://www.google.com/search?q=Iron+Mountain+IRM+stock+short+seller+report+October+28+2026) 4. [StockTitan, Iron Mountain (IRM) news feed: Q2 2026 results summary (5 August 2026), raised guidance, dividend declaration, 6.250% senior notes due 2035 (15 June 2026), Q3 2026 earnings date (15 October 2026)](https://www.stocktitan.net/news/IRM/) 5. [Google Finance, Iron Mountain Inc (IRM) quote page: prices, analyst ratings, quarterly income statement, accessed 30 October 2026](https://www.google.com/finance/quote/IRM:NYSE) 6. [MarketBeat, Iron Mountain (IRM) Short Interest Ratio & Short Volume, FINRA data through 15 October 2026, published 26 October 2026](https://www.marketbeat.com/stocks/NYSE/IRM/short-interest/) 7. [Iron Mountain, quarterly figures from SEC filings (capex, operating cash flow, debt, cash), retrieved 30 October 2026](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001020569) 8. [MoneyShow (Tom Hutchinson, Cabot Dividend Investor), IRM: Scoop Up this Specialty REIT After its Recent Pullback, 22 October 2026](https://finance.yahoo.com/real-estate/articles/irm-scoop-specialty-reit-recent-050100467.html) 9. [Gotham City Research, The Dark Side of Iron Mountain: from a Melting Ice Cube, to a House on Fire, 19 November 2025](https://www.gothamcityresearch.com/post/the-dark-side-of-iron-mountain-from-a-melting-ice-cube-to-a-house-on-fire) 10. [The Inference, AI debt now has two prices: 15% for CoreWeave, 6.25% for Iron Mountain, 17 October 2026](https://theinference.org/article/ai-debt-now-has-two-prices-15-for-coreweave-6-25-for-iron-mountain) --- A short seller says Iron Mountain's data center bet barely covers its interest bill. The stock rose. — The Inference. Canonical: https://theinference.org/article/a-short-seller-says-iron-mountain-s-data-center-bet-barely-covers-its-interest-bill-the-stock-rose