Simpson Manufacturing Co., Inc.
US ˙ NYSE ˙ US8290731053

SecuritySSD / Simpson Manufacturing Co., Inc.
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership870,425 shares
Latest Disclosed Value $ 149,369,726
Dimensional Fund Advisors Lp reports 0.89% decrease in ownership of SSD / Simpson Manufacturing Co., Inc.

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 870,425 shares of Simpson Manufacturing Co., Inc. (US:SSD) valued at $149,382,338 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 878,270 shares of Simpson Manufacturing Co., Inc.. This represents a change in shares of -0.89% during the quarter. The current value of the position is $161,385,499 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)
2026-05-07 2026-03-31 13F SIMPSON MFG COM 829073105 870,425 -7,845 -0.89 149,370 5.32 0.0310
2026-02-12 2025-12-31 13F SIMPSON MFG COM 829073105 878,270 31,744 3.75 141,826 0.05 0.0298
2025-11-12 2025-09-30 13F SIMPSON MFG COM 829073105 846,526 -16,599 -1.92 141,758 5.74 0.0304
2025-08-12 2025-06-30 13F SIMPSON MFG COM 829073105 863,125 -23,680 -2.67 134,060 -3.76 0.0310
2025-05-13 2025-03-31 13F SIMPSON MFG COM 829073105 886,805 -22,743 -2.50 139,296 -7.65 0.0346
2025-02-13 2024-12-31 13F SIMPSON MFG COM 829073105 909,548 -12,857 -1.39 150,831 -14.51 0.0362
2024-11-07 2024-09-30 13F SIMPSON MFG COM 829073105 922,405 -23,016 -2.43 176,428 10.72 0.0428
2024-08-09 2024-06-30 13F SIMPSON MFG COM 829073105 945,421 39,803 4.40 159,343 -14.25 0.0416
2024-05-10 2024-03-31 13F SIMPSON MFG COM 829073105 905,618 -63,548 -6.56 185,815 -3.16 0.0503
2024-02-07 2023-12-31 13F SIMPSON MFG COM 829073105 969,166 -33,388 -3.33 191,882 27.75 0.0560
2023-11-09 2023-09-30 13F SIMPSON MFG COM 829073105 1,002,554 22,046 2.25 150,197 10.60 0.0493
2023-08-09 2023-06-30 13F SIMPSON MFG COM 829073105 980,508 20,159 2.10 135,804 28.99 0.0433
2023-05-12 2023-03-31 13F SIMPSON MFG COM 829073105 960,349 -30,774 -3.10 105,285 120,916.09 0.0355
2023-02-09 2022-12-31 13F SIMPSON MFG COM 829073105 991,123 -16,921 -1.68 88 -99.89 0.0260
2022-11-10 2022-09-30 13F SIMPSON MFG COM 829073105 1,008,044 -22,315 -2.17 79,032 -23.76 0.0303
2022-08-12 2022-06-30 13F SIMPSON MFG COM 829073105 1,030,359 -14,505 -1.39 103,658 -9.02 0.0372
2022-05-13 2022-03-31 13F SIMPSON MFG COM 829073105 1,044,864 -16,862 -1.59 113,938 -22.83 0.0351
2022-02-09 2021-12-31 13F SIMPSON MFG COM 829073105 1,061,726 -34,279 -3.13 147,651 25.93 0.0446
2021-11-12 2021-09-30 13F SIMPSON MFG COM 829073105 1,096,005 -11,514 -1.04 117,246 -4.14 0.0378
2021-08-12 2021-06-30 13F SIMPSON MFG COM 829073105 1,107,519 -7,311 -0.66 122,313 5.77 0.0387
2021-05-14 2021-03-31 13F SIMPSON MFG COM 829073105 1,114,830 -37,532 -3.26 115,641 7.39 0.0382
2021-03-08 2020-12-31 13F/A-2 SIMPSON MANUFACTURING COM 829073105 1,152,362 -21,093 -1.80 107,687 -5.55 0.0389
2021-02-11 2020-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,152,362 -21,093 107,687 38,890.8205
2020-11-12 2020-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,173,455 -34,985 -2.90 114,012 11.84 0.0483
2020-08-13 2020-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,208,440 -84,760 -6.55 101,940 27.18 0.0448
2020-05-14 2020-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,293,200 -30,520 -2.31 80,152 -24.53 0.0418
2020-02-14 2019-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,323,720 -55,871 -4.05 106,202 10.97 0.0387
2019-11-12 2019-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,379,591 -91,285 -6.21 95,700 -2.10 0.0372
2019-08-13 2019-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,470,876 -97,742 -6.23 97,754 5.15 0.0380
2019-08-12 2019-03-31 13F/A-2 SIMPSON MANUFACTURING COM 829073105 1,568,618 -107,903 -6.44 92,969 2.45 0.0370
2019-05-10 2019-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,568,618 -107,903 92,969
2019-02-26 2018-12-31 13F/A-1 SIMPSON MANUFACTURING COM 829073105 1,676,521 -24,462 -1.44 90,750 -26.37 0.0411
2019-02-13 2018-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,676,521 -24,462 90,750
2018-11-13 2018-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,700,983 -87,254 -4.88 123,253 10.83 0.0469
2018-08-10 2018-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,788,237 -37,145 -2.03 111,210 5.79 0.0443
2018-05-11 2018-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,825,382 15,100 0.83 105,124 1.15 0.0438
2018-02-12 2017-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,810,282 31,442 1.77 103,929 19.14 0.0431
2017-11-13 2017-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,778,840 28,126 1.61 87,234 14.00 0.0381
2017-08-11 2017-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,750,714 7,080 0.41 76,524 1.85 0.0353
2017-05-12 2017-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,743,634 64,148 3.82 75,133 2.25 0.0359
2017-02-09 2016-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,679,486 73,078 4.55 73,478 4.07 0.0367
2016-11-10 2016-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,606,408 16,283 1.02 70,602 11.09 0.0382
2016-08-09 2016-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,590,125 68,985 4.54 63,556 9.46 0.0366
2016-05-13 2016-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,521,140 77,767 5.39 58,061 17.79 0.0348
2016-02-10 2015-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,443,373 83,265 6.12 49,292 8.22 0.0307
2015-11-13 2015-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,360,108 24,932 1.87 45,550 0.34 0.0299
2015-08-14 2015-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,335,176 64,339 5.06 45,396 -4.41 0.0278
2015-05-14 2015-03-31 13F SIMPSON MANUFACTURING COM 829073105 1,270,837 104,231 8.93 47,491 17.65 0.0300
2015-02-06 2014-12-31 13F SIMPSON MANUFACTURING COM 829073105 1,166,606 65,934 5.99 40,365 25.80 0.0265
2014-11-13 2014-09-30 13F SIMPSON MANUFACTURING COM 829073105 1,100,672 59,782 5.74 32,086 -15.22 0.0227
2014-08-08 2014-06-30 13F SIMPSON MANUFACTURING COM 829073105 1,040,890 67,595 6.94 37,847 10.07 0.0263
2014-05-14 2014-03-31 13F SIMPSON MANUFACTURING COM 829073105 973,295 67,006 7.39 34,385 3.30 0.0257
2014-02-12 2013-12-31 13F SIMPSON MANUFACTURING COM 829073105 906,289 59,001 6.96 33,288 20.63 0.0259
2013-11-13 2013-09-30 13F SIMPSON MANUFACTURING COM 829073105 847,288 41,350 5.13 27,596 16.39 0.0239
2013-08-15 2013-06-30 13F SIMPSON MANUFACTURING COM 829073105 805,938 805,938 23,710 0.0223
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.