BXP, Inc. (BXP) stock intrinsic value fair value estimate & owner earnings analysis

BXP owns and develops premier office and life-science (lab) buildings concentrated in Boston/Cambridge, New York, Washington D.C., San Francisco and Los Angeles, plus some retail and residential space. No single tenant is more than 10% of lease revenue. We start from the cash the business generates after the recurring cost of maintaining its properties (building improvements and tenant/releasing costs), but before new-development spending, which we treat as discretionary growth investment rather than a cost of keeping today's portfolio running. Over the last five years this figure has run $5.50-$6.66 per share; we anchor on the five-year median of about $5.98, using the recent period because office demand has genuinely shifted since the pandemic and older years describe a different business. Two judgments matter here. First, ground-up construction/lab redevelopment spend (~$500-700M/year) is treated as growth capital, while tenant-improvement and building-improvement spend needed to re-lease existing space (elevated recently, ~$555M in fiscal 2025 vs ~$448M the year before) is treated as a real recurring cost. Second, BXP has recorded large non-cash losses on unconsolidated joint ventures (~$240M in 2023, ~$343M in 2024, ~$104M in 2025); these are added back correctly since they're non-cash, but the repeated pattern of write-offs is reflected in our bear case rather than the earnings level. Fiscal 2025 owner earnings fell about 20% to $4.80/share. Roughly $1.10 of that decline is simply the exclusion of a one-time 2025 property-sale gain (correctly excluded); the rest is a jump in releasing costs from a wave of lease turnover. Adjusted for the one-time item, earnings were roughly flat year over year, and that flat trajectory -- not a rebound -- is what we built our near-term growth assumption on. Our base case assumes roughly flat earnings near-term, then modest 1-2%/year growth. Our bear case (~10th percentile) assumes softening office demand, declining occupancy from today's ~88%, a slower lease-up of BXP's Cambridge lab pipeline given current oversupply in that submarket, and higher interest costs as largely fixed-rate debt refinances at today's higher rates. Our bull case (~90th percentile) assumes the flight-to-quality trend already benefiting BXP's trophy buildings continues, occupancy recovers toward the low 90s, and the lab pipeline eventually leases up well, producing roughly 4%/year growth. Because BXP's properties sit on land in supply-constrained cities and the company continuously reinvests in them (already subtracted above), we don't treat this as a business with a fixed end date. We assume the portfolio keeps earning cash indefinitely beyond year ten, with modest (~1%/year) growth to stay conservative -- but this long-run assumption still makes up roughly half to two-thirds of estimated value in every case, more than we'd like, reflecting the long asset life of real estate. Putting this together: we estimate the shares are worth roughly $79 in our bear case, $127 in our base case, and $154 in our bull case. Given leverage and leasing risk, the margin-of-safety price is set at a real discount -- around $96/share -- and confidence in that price would be higher once the lab pipeline and portfolio occupancy show the leasing risk in our bear case isn't materializing. One note on data: our full-text access to BXP's filings covered through the fiscal-2023 10-K; fiscal 2024 and 2025 figures were built from the underlying financial data tags rather than a full line-by-line read of those two years' cash-flow statements. Every year we could cross-check both ways agreed within rounding.