Simon Property Group, Inc.

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 1,288 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

• UPREIT structure, handled per the brief's specific warning for this company. Simon Property Group, Inc. (the listed REIT, 'Simon') is the sole general partner of Simon Property Group, L.P. (the 'Operating Partnership'). As of 30 Jun 2026, Simon owned an 85.3% interest in the Operating Partnership (10-Q); the remaining 14.7% is held by limited partners as OP units, which are NOT shares of Simon common stock and are excluded from company.shares_outstanding. As of 16 Mar 2026 (2026 proxy) the Operating Partnership had 380,912,144 total units outstanding, of which Simon held 324,848,186 (85.3%) directly or indirectly, leaving roughly 56.06 million limited-partner units outside Simon's own ownership.
• company.shares_outstanding = 323,551,515 is Simon Property Group, Inc.'s common stock outstanding as of 30 Jun 2026 (10-Q cover page), which also states 8,000 shares of Class B common stock outstanding (included separately in share_classes, immaterial to any percentage calculation). This is the correct denominator per the brief: NOT the Operating Partnership's 380,912,144 total units, and NOT a combined shares-plus-units figure. Popular data aggregators (e.g. stockanalysis.com, checked 17 Aug 2026) report SPG 'shares outstanding' as approximately 379.39 million and market cap as approximately $84.10 billion, which appears to be the total Operating Partnership unit count (common shares plus all limited-partner units), not Simon's own common share count; this file does not use that figure. market_cap_usd here (about $71.72 billion) is computed as 323,551,515 x $221.67 (stockanalysis.com closing price, 17 Aug 2026).
• Every register row's shares field, and the holdings-side Klepierre row, are stated in actual listed shares only; wherever a source reported a figure that mixed common stock with OP units or LTIP units (the MSA Group / Melvin Simon & Associates row and four named executive rows in the 2026 proxy's Ownership of Equity Securities table), the units were split out into method_note and excluded from shares, per the brief's explicit instruction for this company.
• The Taubman Realty Group, LLC (TRG) is NOT included as a holding. Simon held an 88% noncontrolling (equity-method) interest in TRG through 31 Oct 2025, when it acquired the remaining 12% for approximately $0.9 billion (the 'TRG Acquisition'), making TRG a wholly owned, consolidated subsidiary from that date. As of the most recent 10-Q and 10-K, TRG is excluded per the brief's 'wholly owned operating subsidiary' exclusion rather than reported as a stake.
• Authentic Brands Group (ABG) is NOT included as a holding. Simon sold all of its remaining interest in ABG during Q1 2024 for $1.2 billion cash (pre-tax gain of $414.8 million), per the FY2025 10-K. It is a past, fully divested position, not a current stake; it is mentioned in the 2026 proxy only in the context of a compensation dispute over incentive-plan payouts tied to that 2024 monetization, not as a current holding.
• Combined-balance trap: the 10-Q's 'Investment in unconsolidated entities, at equity' totaled $1,250.2 million at 30 Jun 2026 ($1,525.6 million at 31 Dec 2025), per its own XBRL tagging this balance EXCLUDES Klepierre and TRG/other platform investments and instead covers the broader 'real estate joint ventures' bucket. Of that bucket, only the Japan (Mitsubishi Estate, $263.5 million) and South Korea (Shinsegae, $212.3 million) Premium Outlet joint ventures are individually sized in the filing and are reported as holdings above ($475.8 million combined, roughly 38% of the $1,250.2 million total). The remainder of that combined balance covers: two full-price mall JVs in China and two in South Korea (ownership 'ranges from 17% to 49%', no per-property value given); a European investee with interests in 12 Designer Outlet properties (legal ownership 'ranged from 23% to 94%', no per-property value given); and a 50% noncontrolling interest in an unnamed 'European property management and development company.' None of these is individually sized, so none is reported as a holdings row here; per the brief's rule against assigning a combined balance to an unsized investee, they are recorded only here and in unknowns.
• Similarly, Simon's 'other platform investments' (Catalyst Brands LLC 31.3%, SPARC Holdings 33.3%, Rue Gilt Groupe 45%, Jamestown 50%, and Phoenix Retail LLC/Express 39.4%) share ONE combined summary financial table in the 10-Q (combined total revenues of $2,593.5 million for Q2 2026 and $4,847.2 million for H1 2026, after intercompany eliminations), with no per-investee balance-sheet carrying value disclosed. All five percentages are individually and separately disclosed and are reported as holdings rows above; every value_usd for these five is null for the same combined-balance reason.
• Klepierre's ownership fell from 22.2% (63,355,252 shares) at 31 Dec 2025 to 20.7% (59,280,541 shares) at 30 Jun 2026, driven by a Q1 2026 exchange of 4,074,711 Klepierre shares to settle conversion of EUR110.3 million of the Operating Partnership's exchangeable bonds. The 30 Jun 2026 figures (most current) are used.
• Register self-gate, computed exactly as the chart computes it (members counted at full value, the aggregate counted at its residual against the container it rolls up into, everything else at full value): 16 register rows, summing to 156,037,121 shares against 323,551,515 shares outstanding, or 48.23%. This sits above the 25 to 45 percent range the brief calls typical but within the 15 to 55 percent band it calls acceptable; the concentration is institutional, not a double-counted holder: the top 10 filed 13F rows alone sum to 153,103,052 shares (47.32%), led by Vanguard at 14.99% and BlackRock at 11.52%, both plain 13F-HR figures with no unit or thousands adjustments left unresolved. No single holder or vehicle was found that would explain the total as an error rather than genuine concentration.
• Two thousands-trap filers were caught and rescaled for this company, matching the brief's warning: T. Rowe Price Associates, Inc. (value column in thousands, corrected $920,309 to $920,309,000) and Cohen & Steers, Inc. (value column in thousands, corrected $1,312,965 to $1,312,965,000). Both corrections were verified against the approximately $223.6 to $223.65 per-share cluster implied by every other Q2 2026 13F filer holding CUSIP 828806109.
• Vanguard case for this company (per the brief's required check): Vanguard Group Inc's parent CIK 0000102909 filed Form 13F-NT (a notice carrying no holdings) for the quarter ended 30 Jun 2026, confirmed directly against its EDGAR submissions feed rather than assumed. Per the brief's rule, the two successor entities were summed rather than substituting a single row.
• T. Rowe Price Investment Management, Inc. (CIK 0001897612) and Capital International Investors (CIK 0001562230, part of the Capital Group family) were each individually checked and confirmed to hold zero SPG shares for Q2 2026 (CUSIP 828806109 absent from each filer's full information table), per the brief's requirement to check all mandated CIKs rather than assume.