Advanced Drainage Systems, Inc.
US ˙ NYSE ˙ US00790R1041

SecurityWMS / Advanced Drainage Systems, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership169,654 shares
Latest Disclosed Value $ 24,570,752
Sei Investments Co reports 5.40% decrease in ownership of WMS / Advanced Drainage Systems, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 169,654 shares of Advanced Drainage Systems, Inc. (US:WMS) valued at $24,570,989 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 179,347 shares of Advanced Drainage Systems, Inc.. This represents a change in shares of -5.40% during the quarter. The current value of the position is $22,480,852 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)
2026-02-13 2025-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 169,654 -9,693 -5.40 24,571 -1.23 0.0243
2025-11-13 2025-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 179,347 -7,923 -4.23 24,875 15.65 0.0267
2025-08-14 2025-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 187,270 59,868 46.99 21,509 55.39 0.0249
2025-05-14 2025-03-31 13F/A-1 ADVANCED DRAIN SYS INC DEL COM 00790R104 127,402 87,954 222.96 13,842 203.55 0.0178
2025-05-13 2025-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 40,386 938 4,611 0.0050
2025-02-11 2024-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 39,448 -38,759 -49.56 4,560 -62.90 0.0059
2024-11-12 2024-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 78,207 4,267 5.77 12,291 3.63 0.0160
2024-08-13 2024-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 73,940 -1,698 -2.24 11,859 -8.97 0.0168
2024-05-07 2024-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 75,638 -4,811 -5.98 13,028 15.14 0.0191
2024-02-14 2023-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 80,449 -606 -0.75 11,314 22.63 0.0182
2023-11-14 2023-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 81,055 -3,182 -3.78 9,227 -3.74 0.0166
2023-08-11 2023-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 84,237 -20,505 -19.58 9,585 8.66 0.0167
2023-05-12 2023-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 104,742 43,982 72.39 8,820 77.11 0.0164
2023-02-10 2022-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 60,760 -210,949 -77.64 4,981 -85.26 0.0111
2022-11-14 2022-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 271,709 30,485 12.64 33,792 55.95 0.0754
2022-08-15 2022-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 241,224 111,611 86.11 21,668 41.39 0.0468
2022-05-13 2022-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 129,613 22,202 20.67 15,325 5.02 0.0308
2022-02-14 2021-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 107,411 5,308 5.20 14,592 32.16 0.0274
2021-11-12 2021-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 102,103 10,704 11.71 11,041 3.63 0.0232
2021-08-06 2021-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 91,399 48,805 114.58 10,654 152.11 0.0236
2021-05-12 2021-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 42,594 21,086 98.04 4,226 135.04 0.0106
2021-02-08 2020-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 21,508 -4,237 -16.46 1,798 11.75 0.0046
2020-12-04 2020-09-30 13F/A-1 ADVANCED DRAIN SYS INC DEL COM 00790R104 25,745 9,907 62.55 1,609 104.97 0.0047
2020-11-06 2020-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 25,745 9,907 1,609 3,874.1143
2020-08-17 2020-06-30 13F/A-1 ADVANCED DRAIN SYS INC DEL COM 00790R104 15,838 -10,665 -40.24 785 0.26 0.0024
2020-08-11 2020-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 11,458 -15,045 466 1,264.0498
2020-05-14 2020-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 26,503 810 3.15 783 -21.54 0.0029
2020-02-06 2019-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 25,693 25,693 998 0.0030
2018-08-03 2018-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 0 -4,646 -100.00 0 -100.00
2018-05-11 2018-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 4,646 -5,986 -56.30 120 -52.76 0.0005
2018-02-08 2017-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 10,632 -4,893 -31.52 254 -19.11 0.0009
2017-11-06 2017-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 15,525 5,178 50.04 314 50.96 0.0011
2017-07-31 2017-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 10,347 3,199 44.75 208 32.48 0.0008
2017-05-05 2017-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 7,148 7,148 157 0.0007
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.