Advanced Drainage Systems, Inc.
MX ˙ BMV ˙ US00790R1041
SecurityMX:WMS / Advanced Drainage Systems, Inc.
InstitutionAsset Management One Co., Ltd.
Latest Disclosed Ownership20,231 shares
Latest Disclosed Value $ 2,774,277
Asset Management One Co., Ltd. reports 1.25% increase in ownership of WMS / Advanced Drainage Systems, Inc.

On May 8, 2026 - Asset Management One Co., Ltd. filed a 13F-HR form disclosing ownership of 20,231 shares of Advanced Drainage Systems, Inc. (MX:WMS) valued at $2,774,277 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 19,982 shares of Advanced Drainage Systems, Inc.. This represents a change in shares of 1.25% 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)
2026-05-08 2026-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 20,231 249 1.25 2,774 -6.63 0.0082
2026-01-27 2025-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 19,982 0 0.00 2,972 7.22 0.0083
2025-10-22 2025-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 19,982 4,574 29.69 2,772 56.64 0.0080
2025-07-31 2025-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 15,408 0 0.00 1,770 5.68 0.0055
2025-04-23 2025-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 15,408 0 0.00 1,674 -5.96 0.0058
2025-01-30 2024-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 15,408 296 1.96 1,781 -25.05 0.0061
2024-10-30 2024-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 15,112 -3,259 -17.74 2,375 -19.38 0.0085
2024-07-18 2024-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 18,371 -836 -4.35 2,947 -10.94 0.0113
2024-05-02 2024-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 19,207 -3,055 -13.72 3,308 4.25 0.0128
2024-01-24 2023-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 22,262 -2,265 -9.23 3,173 13.69 0.0128
2023-10-19 2023-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 24,527 0 0.00 2,792 0.04 0.0124
2023-07-31 2023-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 24,527 -4,445 -15.34 2,791 14.39 0.0118
2023-04-25 2023-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 28,972 0 0.00 2,440 1.63 0.0111
2023-02-06 2022-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 28,972 0 0.00 2,401 -33.39 0.0117
2022-11-04 2022-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 28,972 -19,599 -40.35 3,603 -17.63 0.0183
2022-07-29 2022-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 48,571 -5,524 -10.21 4,374 -31.94 0.0205
2022-05-13 2022-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 54,095 2,499 4.84 6,427 -8.03 0.0251
2022-02-09 2021-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 51,596 0 0.00 6,988 25.21 0.0243
2021-11-02 2021-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 51,596 3,773 7.89 5,581 0.13 0.0214
2021-08-03 2021-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 47,823 5,798 13.80 5,574 28.31 0.0207
2021-05-14 2021-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 42,025 -1,052 -2.44 4,344 22.47 0.0173
2021-02-12 2020-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 43,077 -5,418 -11.17 3,547 17.14 0.0146
2020-11-13 2020-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 48,495 -3,801 -7.27 3,028 17.23 0.0139
2020-08-14 2020-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 52,296 -4,244 -7.51 2,583 55.14 0.0127
2020-05-14 2020-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 56,540 -2,873 -4.84 1,665 -27.86 0.0097
2020-02-14 2019-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 59,413 -8,948 -13.09 2,308 4.62 0.0104
2019-11-14 2019-09-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 68,361 -4,387 -6.03 2,206 -7.51 0.0106
2019-08-14 2019-06-30 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 72,748 -4,720 -6.09 2,385 19.49 0.0117
2019-05-15 2019-03-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 77,468 -5,905 -7.08 1,996 -1.24 0.0108
2019-02-13 2018-12-31 13F ADVANCED DRAIN SYS INC DEL COM 00790R104 83,373 83,373 2,021 0.0048
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.