Simon Property Group, Inc.
MX ˙ BMV ˙ US8288061091
SecurityMX:SPG / Simon Property Group, Inc.
InstitutionBoston Partners
Latest Disclosed Ownership2,302,071 shares
Latest Disclosed Value $ 429,420,591
Boston Partners reports 4.20% decrease in ownership of SPG / Simon Property Group, Inc.

On May 11, 2026 - Boston Partners filed a 13F-HR form disclosing ownership of 2,302,071 shares of Simon Property Group, Inc. (MX:SPG) valued at $429,420,591 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 2,403,041 shares of Simon Property Group, Inc.. This represents a change in shares of -4.20% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-11 2026-03-31 13F SIMON PPTY GROUP INC COM 828806109 2,302,071 -100,970 -4.20 429,421 -3.46 0.4498
2026-02-13 2025-12-31 13F SIMON PPTY GROUP INC COM 828806109 2,403,041 -43,231 -1.77 444,823 -3.10 0.4606
2025-11-13 2025-09-30 13F SIMON PPTY GROUP INC COM 828806109 2,446,272 51,748 2.16 459,035 19.23 0.4713
2025-08-12 2025-06-30 13F/A-1 SIMON PPTY GROUP INC COM 828806109 2,394,524 -47,331 -1.94 384,996 -5.04 0.4275
2025-08-07 2025-06-30 13F SIMON PPTY GROUP INC COM 828806109 2,394,524 -47,331 384,996 0.1768
2025-05-13 2025-03-31 13F SIMON PPTY GROUP INC COM 828806109 2,441,855 -62,645 -2.50 405,449 -5.99 0.4903
2025-02-11 2024-12-31 13F SIMON PPTY GROUP INC COM 828806109 2,504,500 162,764 6.95 431,304 8.96 0.5246
2024-11-12 2024-09-30 13F SIMON PPTY GROUP INC COM 828806109 2,341,736 37,379 1.62 395,829 13.16 0.4672
2024-08-14 2024-06-30 13F SIMON PPTY GROUP INC COM 828806109 2,304,357 -16,871 -0.73 349,789 -3.68 0.4345
2024-05-28 2024-03-31 13F/A-1 SIMON PPTY GROUP INC COM 828806109 2,321,228 92,648 4.16 363,165 14.25 0.4326
2024-05-13 2024-03-31 13F SIMON PPTY GROUP INC COM 828806109 2,321,228 92,648 363,165 0.1797
2024-02-07 2023-12-31 13F SIMON PPTY GROUP INC COM 828806109 2,228,580 183,702 8.98 317,881 43.89 0.4210
2023-11-08 2023-09-30 13F SIMON PPTY GROUP INC COM 828806109 2,044,878 1,890 0.09 220,918 -6.37 0.3059
2023-08-10 2023-06-30 13F SIMON PPTY GROUP INC COM 828806109 2,042,988 14,100 0.69 235,940 3.85 0.3176
2023-05-09 2023-03-31 13F SIMON PPTY GROUP INC COM 828806109 2,028,888 2,022,530 31,810.79 227,184 30,353.49 0.3123
2023-02-08 2022-12-31 13F SIMON PPTY GROUP INC COM 828806109 6,358 147 2.37 747 33.93 0.0010
2022-11-09 2022-09-30 13F SIMON PPTY GROUP INC COM 828806109 6,211 -11 -0.18 557 -5.91 0.0008
2022-08-10 2022-06-30 13F SIMON PPTY GROUP INC COM 828806109 6,222 135 2.22 592 -26.09 0.0008
2022-05-10 2022-03-31 13F SIMON PPTY GROUP INC COM 828806109 6,087 177 2.99 801 -15.15 0.0010
2022-02-04 2021-12-31 13F SIMON PPTY GROUP INC COM 828806109 5,910 -507 -7.90 944 13.19 0.0011
2021-11-05 2021-09-30 13F SIMON PPTY GROUP INC COM 828806109 6,417 -925 -12.60 834 -12.94 0.0011
2021-08-12 2021-06-30 13F SIMON PPTY GROUP INC COM 828806109 7,342 -4,180 -36.28 958 -26.93 0.0012
2021-05-10 2021-03-31 13F SIMON PPTY GROUP INC COM 828806109 11,522 -1,908 -14.21 1,311 14.50 0.0018
2021-02-10 2020-12-31 13F/A-1 SIMON PPTY GROUP INC COM 828806109 13,430 431 3.32 1,145 36.15 0.0018
2021-02-04 2020-12-31 13F SIMON PPTY GROUP INC COM 828806109 13,430 431 1,145 686.9319
2020-11-13 2020-09-30 13F/A-1 SIMON PPTY GROUP INC COM 828806109 12,999 -167 -1.27 841 -6.56 0.0015
2020-11-09 2020-09-30 13F SIMON PPTY GROUP INC COM 828806109 13,166 0 900 660.7072
2020-08-12 2020-06-30 13F SIMON PPTY GROUP INC COM 828806109 13,166 -3,223 -19.67 900 0.11 0.0017
2020-05-13 2020-03-31 13F SIMON PPTY GROUP INC COM 828806109 16,389 15,843 2,901.65 899 1,009.88 0.0018
2020-02-06 2019-12-31 13F/A-1 SIMON PPTY GROUP INC COM 828806109 546 546 81 0.0001
2020-02-05 2019-12-31 13F SIMON PPTY GROUP INC COM 828806109 546 81 0.0001
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.