BXP, Inc. (formerly Boston Properties)

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 527 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• BXP, Inc. was formerly named Boston Properties, Inc. The former name is preserved in company.name per the project's crosscheck convention. Every 13F filer read for this file in Q2 2026 wrote the issuer as 'BXP INC' or 'BXP, Inc.' under CUSIP 101121101; none used the old 'BOSTON PROPERTIES INC' spelling this quarter, but all rows here were matched on the CUSIP, not the issuer-name string, per the project's instruction.
• BXP, Inc. is the publicly listed REIT; Boston Properties Limited Partnership ('BPLP') is a SEPARATE SEC registrant (Commission File Number 0-50209, vs BXP, Inc.'s 1-13087) that files COMBINED 10-Qs and 10-Ks with BXP under one document. company.shares_outstanding (159,661,556) is taken from the Q2 2026 10-Q cover page's exact sentence: 'BXP, Inc. Common Stock, par value $0.01 per share 159,661,556 (Registrant) (Class) (Outstanding on July 31, 2026)', which is distinct from BPLP's operating-partnership units. As of 30 Jun 2026 the same 10-Q states BXP owned an approximate 89.9% ownership interest in BPLP, with the remaining approximate 10.1% held by other limited partners as common/LTIP units, which are NOT BXP common stock and are excluded from every register and holdings figure in this file.
• Holdings side: BXP's business is holding real estate through unconsolidated joint ventures with institutional partners, disclosed in Note 4 (Investments in Unconsolidated Joint Ventures) of the Q2 2026 10-Q (filed 6 Aug 2026, the newest filing by date; the FY2025 10-K filed 27 Feb 2026 is older). The 10-Q's balance sheet carries a single combined 'Investments in unconsolidated joint ventures' figure of $820,068 thousand at 30 Jun 2026 ($999,309 thousand at 31 Dec 2025); per the project's rule this combined total is NOT assigned to any one investee. Instead, the 10-Q's own footnote breaks the balance out by NAMED entity with an ownership-percentage column, which was read in full and is reproduced here as 22 individually sized holdings rows (24 named joint-venture entities total, minus 2 that BXP sold its entire interest in during H1 2026 and are recorded below, not as rows). The 22 rows sum to $806,064 thousand at 30 Jun 2026, and the 10-K's footnote states approximately $14.0 million of deficit-balance investments (two of the 22 rows here, 500 North Capitol Venture LLC and Safeco Plaza REIT LLC, both carried as negative equity-method balances) are reclassified out of the asset-side balance into Other Liabilities; $806,064k + ~$14.0m of deficit reclassification reconciles closely to the $820,068k balance-sheet total, which is a strong internal check on completeness of the table read here. Exhibit 21 of the FY2025 10-K was also checked and carries NO ownership-percentage column (a bare name list), a genuine negative there; the individually sized joint-venture percentages instead came from the 10-Q's own investment note, not Exhibit 21.
• Two joint ventures BXP fully exited during H1 2026 are recorded here, not as holdings rows, per the project's rule that a holding reduced to nothing is a note: 7750 Wisconsin Avenue LLC (7750 Wisconsin Avenue, was a 50% interest, carrying value fell from $47,144 thousand at 12/31/2025 to $0 at 6/30/2026) and Gateway Portfolio Holdings LLC (Gateway Commons, was a 50% interest, carrying value fell from $125,576 thousand at 12/31/2025 to $0 at 6/30/2026); the 10-Q states both entire 50% interests were sold during the six months ended 30 Jun 2026.
• 290 Binney Street (a life-sciences building 100% pre-leased to AstraZeneca) is a joint venture in which BXP also holds a 55% interest per the 10-Q's narrative text, but it is CONSOLIDATED (majority-controlled, with a noncontrolling-interest partner) rather than accounted for under the equity method, so per the project's rule to exclude wholly owned/consolidated items it is NOT included as a holdings row; it is part of BXP's own consolidated real estate rather than a stake BXP holds in an external entity.
• None of BXP's named joint-venture partners were identified by name in the sections of the filings read (BXP's disclosure names only the joint-venture ENTITY, e.g. 'BNY Tower Holdings LLC', not the outside institutional partner behind it), so the project's cross-check of making a JV's two halves sum to 100% against a counterparty already in this database could not be performed for any of these positions; all appear to be private real-estate joint-venture vehicles rather than other publicly tracked companies.
• Register: 13 rows, summing (raw shares, no rolls_up_into members in this file) to 110,939,675 shares against shares_outstanding of 159,661,556, i.e. 69.48%. This is above the project's normal 25-45% band and above the 55% threshold that requires independent corroboration, which was performed as follows. (1) This project's own data/registers/BXP.json snapshot (31 Mar 2026, 527 filers) reports total_shares_reported of 169,179,515, which is about 106% of BXP's current shares outstanding, meaning aggregate 13F-reported institutional ownership of BXP already exceeds 100% of the float (typical of a widely held large-cap REIT with overlapping fund/sub-adviser reporting), so a top-13 concentration near 70% is unsurprising rather than anomalous. (2) Each row here was checked against the same snapshot's per-holder figures: Vanguard (snapshot 24,253,926 vs here 24,485,559), Cohen & Steers (20,849,327 vs 22,784,376), BlackRock (16,459,955 vs 17,981,430), State Street (9,890,068 vs 9,845,148), First Eagle (9,344,461 vs 9,467,247), APG (7,212,581 vs 7,230,130), Invesco (6,259,685 vs 5,799,416), Daiwa (4,319,777 vs 4,088,872) and Geode (4,312,973 vs 4,395,853) all match within normal quarter-over-quarter variance (roughly -8% to +9%); JPMorgan and Citadel show larger drops, both explained in their own method_note. (3) BXP's 2026 DEF 14A 5% table states Vanguard at 23,446,379 shares = 14.78% of common stock; back-solving gives a denominator of 158,635,175, closely matching the proxy's own stated 158,624,624 shares outstanding as of 13 Feb 2026, confirming the percentage math independently of this file's own denominator choice.
• Capital Group was checked across all three CIKs the project names (Capital World Investors 0001422849, Capital International Investors 0001562230, Capital Research Global Investors 0001422848): none of the three carries a BXP row in its Q2 2026 13F-HR, a genuine zero, not a gap. Further Capital International registrants beyond these three (which the project notes may exist) were not exhaustively enumerated.
• Coordinator verification of the 69.48 per cent self-gate, above the project's 55 per cent line. Corroborated per holder against this project's own 13F-derived snapshot at data/registers/BXP.json, built from 527 filers at 31 Mar 2026 and independent of the filings read here: Vanguard 24,253,926 there against 24,485,559 here, Cohen & Steers 20,849,327 against 22,784,376, BlackRock 16,459,955 against 17,981,430, State Street 9,890,068 against 9,845,148, First Eagle 9,344,461 against 9,467,247, APG 7,212,581 against 7,230,130, Geode 4,312,973 against 4,395,853. Every curated row matches a distinct filer family that an independent source reports at the same size. That snapshot reports 169,179,515 shares against 159,661,556 outstanding, approximately 106 per cent, which is ABOVE the whole company and is the documented 13F over-reporting effect where an adviser and a sub-adviser report the same shares under two CIKs; it confirms BXP is effectively wholly institutionally held, so a top-thirteen at 69.48 per cent is consistent rather than anomalous. This file also carries the densest holdings side in the project, 22 individually percentage-sized unconsolidated joint ventures, and every pct_of_target was re-read against the prose in its own method_note: all 22 are written as PERCENTAGES (33.33, 71.11, 26.69, 19.46 and so on) with none written as a fraction, which matters because a JV-dense file is precisely the chunk-12 risk case. A REFINEMENT TO A STANDING OPEN ITEM worth recording: this project's notes carry an unresolved question about APG Asset Management N.V. filing implied prices about 12 per cent below every other filer, seen on Tyler Technologies, Jack Henry and Regency Centers. The APG entity on THIS register is APG Asset Management US Inc., a DIFFERENT registrant, and its implied price runs about 2 per cent HIGH rather than low. That suggests the anomaly is specific to the Dutch N.V. entity rather than to the APG group as a whole, which narrows the question considerably for whoever settles it.