AMT vs OPEN: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. AMT and OPEN share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined AMT and OPEN exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

American Tower Corporation (NYSE: AMT), founded in 1995 and headquartered in Boston, is a real estate investment trust that owns, operates, and develops multitenant communications real estate. Its core business is leasing vertical space on wireless towers to mobile network operators, government agencies, and broadcasters under long-term contracts with annual escalators, generating 97% of 2025 revenue from property operations. Beyond towers, AMT owns CoreSite, a portfolio of 30 U.S. data centers offering colocation and interconnection services to enterprises, cloud providers, and network operators, which has become a fast-growing second revenue engine. The company manages nearly 150,000 communications sites across the Americas, Europe, Africa, and Asia-Pacific, providing global scale that smaller peers cannot easily replicate.

Full AMT guide

Opendoor Technologies runs an iBuyer platform that lets people sell a home online in days rather than through a traditional listing. The company makes an algorithmic cash offer, buys the home directly, does light repairs and renovation, and resells it, aiming to earn a spread plus service fees on each transaction. Its margins live at the unit level: contribution margin measures what is left after the resale price, holding costs, and selling costs on the homes it moves. Because Opendoor takes ownership of inventory, it carries homes on its own balance sheet and finances them largely with non-recourse asset-backed debt, which makes its economics highly sensitive to how fast it can turn inventory and which direction home prices move.

Full OPEN guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• AMT drivers: 5G Densification and Mid-Band Upgrades; CoreSite and AI-Driven Data Center Demand.
• OPEN drivers: Leverage to a housing recovery; Asset-lighter, faster operating model.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The most immediate risk is customer concentration: in 2025, four carriers (T-Mobile at 18%, AT&T at 17%, Verizon at 14%, and Telefonica at 10%) collectively represented roughly 59% of total revenue, so any material lease dispute, consolidation event, or technology shift (such as carriers building private networks or relying on low-earth-orbit satellites) could disproportionately hurt results. For OPEN, the bear case is substantial.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick AMT if you believe its drivers more; OPEN if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the AMT and OPEN guides.

AMT. AMT's trailing P/E of approximately 27x is well below its own 3-year average of roughly 45x and its 10-year average of roughly 56x, reflecting both earnings normalization after a period of large one-time items and a broader re-rating of rate-sensitive REITs in a higher-for-longer interest rate environment. For tower REITs, investors typically focus on AFFO per share rather than GAAP earnings, because the latter is heavily influenced by depreciation and one-time currency gains or losses. On that basis, FY 2025 delivered high-single-digit AFFO per share growth, and management's 2026 guidance projects continued quarterly revenue in the $2.67 billion to $2.77 billion range per quarter, suggesting mid-single-digit full-year growth if realized.

OPEN. Opendoor trades as a speculative turnaround rather than on conventional earnings multiples, because it is not yet profitable and its results swing with housing activity. Revenue has fallen sharply from prior years as the company bought fewer homes, while unit-level margins have improved. Figures are approximate, drawn from the most recent reported quarter, and can change materially with each housing cycle and each new disclosure.

Headline figures (approximate, 2026-06-27): AMT shows revenue (q1 2026) ~$2.74 billion, revenue (fy 2024, most recent full year) ~$10.13 billion, adjusted ebitda (q1 2026) ~$1.84 billion (margin ~67%), affo per share (q1 2026) ~$2.84 (up ~3.3% year-over-year); OPEN shows revenue (ttm) ~$3.9B, q1 2026 revenue ~$720M, homes sold (q1 2026) ~1,921, contribution margin (q1 2026) ~4.4%.

AMT and OPEN are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined AMT and OPEN exposure against your real portfolio. It is not an investment adviser.