Boston Properties, Inc.
US ˙ NYSE ˙ US1011211018

SecurityBXP / Boston Properties, Inc.
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership69,907 shares
Latest Disclosed Value $ 3,626,426
Janus Henderson Group Plc reports 481.69% increase in ownership of BXP / Boston Properties, Inc.

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 69,907 shares of Boston Properties, Inc. (US:BXP) valued at $3,628,173 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 12,018 shares of Boston Properties, Inc.. This represents a change in shares of 481.69% during the quarter. The current value of the position is $4,337,380 USD.

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)
2026-05-18 2026-03-31 13F/A-1 BXP COM 101121101 69,907 57,889 481.69 3,626 347.10 0.0006
2026-05-15 2026-03-31 13F BXP COM 101121101 69,907 57,889 3,626 0.0007
2026-02-17 2025-12-31 13F BXP COM 101121101 12,018 294 2.51 811 -6.89 0.0004
2025-11-14 2025-09-30 13F BXP COM 101121101 11,724 -494,591 -97.68 872 -97.45 0.0004
2025-08-14 2025-06-30 13F BXP COM 101121101 506,315 -379,145 -42.82 34,147 -43.00 0.0167
2025-05-15 2025-03-31 13F BXP COM 101121101 885,460 151,057 20.57 59,908 9.61 0.0328
2025-02-14 2024-12-31 13F BXP COM 101121101 734,403 716,611 4,027.71 54,655 3,719.29 0.0278
2024-11-14 2024-09-30 13F BXP COM 101121101 17,792 0 0.00 1,431 30.68 0.0007
2024-08-14 2024-06-30 13F BOSTON PROPERTIES COM 101121101 17,792 2,155 13.78 1,095 7.25 0.0006
2024-05-15 2024-03-31 13F BOSTON PROPERTIES COM 101121101 15,637 -65 -0.41 1,021 -7.27 0.0006
2024-02-14 2023-12-31 13F BOSTON PROPERTIES COM 101121101 15,702 -122 -0.77 1,102 17.00 0.0007
2023-11-14 2023-09-30 13F BOSTON PROPERTIES COM 101121101 15,824 1,111 7.55 941 11.23 0.0006
2023-08-14 2023-06-30 13F BOSTON PROPERTIES COM 101121101 14,713 -6,317 -30.04 847 -25.59 0.0005
2023-05-15 2023-03-31 13F BOSTON PROPERTIES COM 101121101 21,030 4,354 26.11 1,137 0.89 0.0007
2023-02-14 2022-12-31 13F BOSTON PROPERTIES COM 101121101 16,676 -39,324 -70.22 1,127 -73.16 0.0008
2023-01-13 2022-09-30 13F/A-1 BOSTON PROPERTIES COM 101121101 56,000 32,806 141.44 4,199 103.34 0.0031
2022-11-14 2022-09-30 13F BOSTON PROPERTIES COM 101121101 56,000 32,806 4,199 0.0031
2022-08-15 2022-06-30 13F BOSTON PROPERTIES COM 101121101 23,194 -18,906 -44.91 2,065 -61.92 0.0014
2022-05-16 2022-03-31 13F BOSTON PROPERTIES COM 101121101 42,100 13,603 47.73 5,423 65.23 0.0026
2022-02-14 2021-12-31 13F BOSTON PROPERTIES COM 101121101 28,497 -146 -0.51 3,282 5.77 0.0014
2021-11-16 2021-09-30 13F BOSTON PROPERTIES COM 101121101 28,643 -7,268 -20.24 3,103 -24.59 0.0014
2021-08-16 2021-06-30 13F BOSTON PROPERTIES COM 101121101 35,911 737 2.10 4,115 15.43 0.0018
2021-05-17 2021-03-31 13F BOSTON PROPERTIES COM 101121101 35,174 0 0.00 3,565 7.25 0.0016
2021-02-16 2020-12-31 13F BOSTON PROPERTIES COM 101121101 35,174 -3,200 -8.34 3,324 7.82 0.0015
2020-11-16 2020-09-30 13F BOSTON PROPERTIES COM 101121101 38,374 2,087 5.75 3,083 -6.01 0.0016
2020-08-14 2020-06-30 13F BOSTON PPTYS LTD PARTNERSHIP COM 101121101 36,287 355 0.99 3,280 -0.94 0.0018
2020-05-14 2020-03-31 13F BOSTON PROPERTIES COM 101121101 35,932 2,113 6.25 3,311 -28.95 0.0023
2020-02-18 2019-12-31 13F BOSTON PROPERTIES COM 101121101 33,819 -35,705 -51.36 4,660 -48.31 0.0024
2019-11-14 2019-09-30 13F BOSTON PROPERTIES COM 101121101 69,524 16,457 31.01 9,015 31.74 0.0049
2019-07-31 2019-06-30 13F BOSTON PROPERTIES COM 101121101 53,067 -1,278 -2.35 6,843 -6.04 0.0037
2019-04-30 2019-03-31 13F BOSTON PROPERTIES COM 101121101 54,345 17,051 45.72 7,283 73.53 0.0040
2019-02-06 2018-12-31 13F BOSTON PROPERTIES COM 101121101 37,294 0 0.00 4,197 -8.58 0.0027
2018-11-09 2018-09-30 13F BOSTON PROPERTIES COM 101121101 37,294 -213 -0.57 4,591 -2.40 0.0025
2018-08-10 2018-06-30 13F BOSTON PROPERTIES COM 101121101 37,507 -23 -0.06 4,704 1.73 0.0027
2018-05-14 2018-03-31 13F BOSTON PROPERTIES COM 101121101 37,530 1,854 5.20 4,624 -0.32 0.0027
2018-03-12 2017-12-31 13F/A-1 BOSTON PROPERTIES COM 101121101 35,676 -3,122 -8.05 4,639 -2.66 0.0029
2018-02-09 2017-12-31 13F BOSTON PROPERTIES COM 101121101 35,676 -3,122 4,639
2017-11-14 2017-09-30 13F BOSTON PROPERTIES COM 101121101 38,798 -25,884 -40.02 4,766 -40.10 0.0031
2017-08-17 2017-06-30 13F/A-1 BOSTON PROPERTIES COM 101121101 64,682 45,417 235.75 7,957 211.92 0.0054
2017-08-14 2017-06-30 13F BOSTON PROPERTIES COM 101121101 64,682 45,417 7,957
2017-05-03 2017-03-31 13F BOSTON PROPERTIES COM 101121101 19,265 300 1.58 2,551 6.92 0.0179
2017-01-30 2016-12-31 13F BOSTON PROPERTIES COM 101121101 18,965 2,558 15.59 2,386 6.71 0.0176
2016-10-24 2016-09-30 13F BOSTON PROPERTIES COM 101121101 16,407 -2,734 -14.28 2,236 -11.45 0.0165
2016-07-29 2016-06-30 13F BOSTON PROPERTIES COM 101121101 19,141 -3,178 -14.24 2,525 -10.97 0.0210
2016-05-12 2016-03-31 13F BOSTON PROPERTIES COM 101121101 22,319 -119,854 -84.30 2,836 -84.36 0.0230
2016-02-03 2015-12-31 13F BOSTON PROPERTIES COM 101121101 142,173 9,500 7.16 18,134 15.41 0.1455
2015-11-16 2015-09-30 13F BOSTON PROPERTIES COM 101121101 132,673 -37,500 -22.04 15,712 -23.69 0.1384
2015-08-17 2015-06-30 13F BOSTON PROPERTIES COM 101121101 170,173 8,555 5.29 20,590 -9.36 0.1618
2015-06-02 2015-03-31 13F/A-1 BOSTON PROPERTIES COM 101121101 161,618 -45,540 -21.98 22,715 -14.80 0.1752
2015-05-15 2015-03-31 13F BOSTON PROPERTIES COM 101121101 161,618 22,715
2015-02-12 2014-12-31 13F BOSTON PROPERTIES COM 101121101 207,158 -12,655 -5.76 26,661 4.79 0.1922
2014-11-12 2014-09-30 13F BOSTON PROPERTIES COM 101121101 219,813 -16,200 -6.86 25,443 -8.76 0.2393
2014-08-13 2014-06-30 13F BOSTON PROPERTIES COM 101121101 236,013 213,800 962.50 27,886 996.15 0.2604
2014-05-08 2014-03-31 13F BOSTON PROPERTIES COM 101121101 22,213 3,500 18.70 2,544 35.54 0.0248
2014-01-14 2013-12-31 13F BOSTON PROPERTIES COM 101121101 18,713 0 0.00 1,877 -6.20 0.0190
2013-11-12 2013-09-30 13F BOSTON PROPERTIES COM 101121101 18,713 0 0.00 2,001 2.09 0.0221
2013-08-15 2013-06-30 13F BOSTON PROPERTIES COM 101121101 18,713 18,713 1,960 0.0229
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.