DUDLEY & SHANLEY, INC. — 13F Holdings & Portfolio
CIK 883511 · latest 13F-HR filed 2026-04-08
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$611.2M
Long-equity book
38
Distinct positions
2026-03-31
Filed 2026-04-08
+4 / −0 / ↑11 / ↓16
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- Fastenal Co.$8.1M +2831.0%
- Kadant Inc.$6.4M +40.9%
- Kornit Digital$5.4M +41.8%
- Badger Meter Inc$4.2M +29.0%
- Allison Transmission$3.2M +19.6%
Top Trims
- Wheaton Precious Mtls-$18.4M -23.4%
- Ryan Specialty Hldngs-$8.5M -34.3%
- Amphenol Corp.-$7.2M -18.8%
- Roper Technologies-$7.1M -90.9%
- Visa Inc.-$4.7M -13.9%
New Positions
- Xylem Inc.$9.7M
- Federal Signal Corp$6.8M
- Waters Corporation$3.5M
- ATHA Energy Corp.$43.8K
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | Wheaton Precious Mtls | WPM | 962879102 | $39.1M | 6.40% | 298,812 | SH |
| 2 | Amphenol Corp. | APH | 032095101 | $31.1M | 5.08% | 245,751 | SH |
| 3 | Service Corp. Int'l | SCI | 817565104 | $30.3M | 4.96% | 367,633 | SH |
| 4 | Analog Devices | ADI | 032654105 | $30.3M | 4.95% | 95,121 | SH |
| 5 | Ametek Inc. | AME | 031100100 | $30.0M | 4.90% | 139,746 | SH |
| 6 | Visa Inc. | V | 92826C839 | $29.4M | 4.80% | 97,166 | SH |
| 7 | Aon plc | AON | G0403H108 | $28.7M | 4.69% | 88,782 | SH |
| 8 | Ecolab Inc. | ECL | 278865100 | $27.9M | 4.57% | 105,008 | SH |
| 9 | Rollins, Inc. | ROL | 775711104 | $24.3M | 3.98% | 455,730 | SH |
| 10 | Ferguson Enterprises | FERG | 31488V107 | $24.3M | 3.98% | 104,175 | SH |
| 11 | Amer. Water Works | AWK | 030420103 | $23.0M | 3.76% | 169,044 | SH |
| 12 | Donaldson Co., Inc. | DCI | 257651109 | $22.9M | 3.75% | 270,405 | SH |
| 13 | Charles Schwab | SCHW | 808513105 | $22.6M | 3.70% | 240,933 | SH |
| 14 | Kadant Inc. | KAI | 48282T104 | $22.1M | 3.62% | 75,735 | SH |
| 15 | Danaher Corp. | DHR | 235851102 | $21.8M | 3.56% | 114,881 | SH |
| 16 | Wheaton Precious Mtls | WPM | 962879102 | $21.0M | 3.44% | 160,573 | SH |
| 17 | Watsco, Inc. | WSO | 942622200 | $20.3M | 3.31% | 55,692 | SH |
| 18 | Allison Transmission | ALSN | 01973R101 | $19.3M | 3.15% | 164,597 | SH |
| 19 | Badger Meter Inc | BMI | 056525108 | $18.6M | 3.04% | 122,150 | SH |
| 20 | Kornit Digital | KRNT | M6372Q113 | $18.4M | 3.01% | 1,254,615 | SH |
| 21 | Ryan Specialty Hldngs | RYAN | 78351F107 | $16.2M | 2.65% | 480,021 | SH |
| 22 | NexGen Energy Ltd. | NXE | 65340P106 | $14.2M | 2.32% | 1,224,500 | SH |
| 23 | Progressive Corp. | PGR | 743315103 | $13.1M | 2.15% | 66,280 | SH |
| 24 | Xylem Inc. | XYL | 98419M100 | $9.7M | 1.58% | 80,830 | SH |
| 25 | Fastenal Co. | FAST | 311900104 | $8.4M | 1.38% | 181,250 | SH |
| 26 | Fiserv Inc. | FISV | 337738108 | $8.0M | 1.31% | 143,923 | SH |
| 27 | Federal Signal Corp | FSS | 313855108 | $6.8M | 1.11% | 62,730 | SH |
| 28 | Agilent Tech, Inc. | A | 00846U101 | $6.3M | 1.03% | 55,200 | SH |
| 29 | HEICO Corp. | HEI | 422806109 | $5.3M | 0.87% | 19,500 | SH |
| 30 | Microsoft Corp. | MSFT | 594918104 | $3.9M | 0.64% | 10,569 | SH |
| 31 | Generac Holdings | GNRC | 368736104 | $3.8M | 0.63% | 19,650 | SH |
| 32 | Waters Corporation | WAT | 941848103 | $3.5M | 0.57% | 11,720 | SH |
| 33 | Ormat Technologies | ORA | 686688102 | $3.1M | 0.51% | 28,000 | SH |
| 34 | Invesco Water ETF | PHO | 46137V142 | $2.2M | 0.36% | 32,780 | SH |
| 35 | Roper Technologies | ROP | 776696106 | $707.7K | 0.12% | 2,000 | SH |
| 36 | Viper Energy Inc | VNOM | 64361Q101 | $361.8K | 0.06% | 7,700 | SH |
| 37 | Stallion Uranium Corp | — | 852919208 | $60.6K | 0.01% | 180,000 | SH |
| 38 | ATHA Energy Corp. | — | 046824108 | $43.8K | 0.01% | 74,500 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-04-08 | $611.2M | 38 | 0000883511-26-000002 |
| 2025-12-31 | 2026-01-09 | $622.2M | 34 | 0000883511-26-000001 |