DUDLEY & SHANLEY, INC. — 13F Holdings & Portfolio
CIK 883511 · latest 13F-HR filed 2026-07-09
DUDLEY & SHANLEY, INC. manages $662.3M in 13F-reported U.S. long-equity assets across 38 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are APH (6.24%), AME (5.10%), V (5.02%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 1 new position, exited 1, added to 17, and trimmed 11.
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.
#311
PALM BEACH, FL 33480
$662.3M
Long-equity book
38
Distinct positions
2026-06-30
Filed 2026-07-09
+1 / −1 / ↑17 / ↓11
vs 2026-03-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- Federal Signal Corp$15.0M +220.6%
- Fastenal Co.$14.3M +169.8%
- Watsco, Inc.$12.2M +60.5%
- Xylem Inc.$11.7M +121.6%
- Amphenol Corp.$10.3M +33.1%
Top Trims
- Badger Meter Inc-$9.3M -49.8%
- Wheaton Precious Mtls-$9.1M -15.2%
- Danaher Corp.-$7.7M -35.3%
- Rollins, Inc.-$3.7M -15.0%
- Analog Devices-$3.6M -11.8%
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 | Amphenol Corp. | APH | 032095101 | $41.3M | 6.24% | 234,451 | SH |
| 2 | Ametek Inc. | AME | 031100100 | $33.8M | 5.10% | 139,731 | SH |
| 3 | Visa Inc. | V | 92826C839 | $33.3M | 5.02% | 96,971 | SH |
| 4 | Wheaton Precious Mtls | WPM | 962879102 | $33.0M | 4.99% | 294,132 | SH |
| 5 | Watsco, Inc. | WSO | 942622200 | $32.5M | 4.91% | 78,012 | SH |
| 6 | Aon plc | AON | G0403H108 | $29.5M | 4.45% | 88,807 | SH |
| 7 | Ecolab Inc. | ECL | 278865100 | $29.2M | 4.40% | 104,693 | SH |
| 8 | Service Corp. Int'l | SCI | 817565104 | $27.9M | 4.22% | 367,783 | SH |
| 9 | Analog Devices | ADI | 032654105 | $26.7M | 4.03% | 67,200 | SH |
| 10 | Ferguson Enterprises | FERG | 31488V107 | $24.7M | 3.73% | 104,225 | SH |
| 11 | Donaldson Co., Inc. | DCI | 257651109 | $24.4M | 3.69% | 272,330 | SH |
| 12 | Kadant Inc. | KAI | 48282T104 | $23.8M | 3.59% | 75,735 | SH |
| 13 | Fastenal Co. | FAST | 311900104 | $22.7M | 3.43% | 472,440 | SH |
| 14 | Amer. Water Works | AWK | 030420103 | $22.3M | 3.36% | 169,344 | SH |
| 15 | Charles Schwab | SCHW | 808513105 | $22.2M | 3.36% | 240,933 | SH |
| 16 | Federal Signal Corp | FSS | 313855108 | $21.8M | 3.28% | 169,285 | SH |
| 17 | Xylem Inc. | XYL | 98419M100 | $21.4M | 3.23% | 181,050 | SH |
| 18 | Rollins, Inc. | ROL | 775711104 | $20.7M | 3.12% | 495,655 | SH |
| 19 | Kornit Digital | KRNT | M6372Q113 | $20.4M | 3.08% | 1,255,265 | SH |
| 20 | Allison Transmission | ALSN | 01973R101 | $18.6M | 2.81% | 165,037 | SH |
| 21 | Wheaton Precious Mtls | WPM | 962879102 | $18.0M | 2.72% | 160,508 | SH |
| 22 | Ryan Specialty Hldngs | RYAN | 78351F107 | $17.6M | 2.65% | 465,146 | SH |
| 23 | Progressive Corp. | PGR | 743315103 | $14.5M | 2.19% | 66,280 | SH |
| 24 | Danaher Corp. | DHR | 235851102 | $14.1M | 2.13% | 74,024 | SH |
| 25 | NexGen Energy Ltd. | NXE | 65340P106 | $11.5M | 1.74% | 1,225,500 | SH |
| 26 | Badger Meter Inc | BMI | 056525108 | $9.3M | 1.41% | 63,000 | SH |
| 27 | Agilent Tech, Inc. | A | 00846U101 | $9.2M | 1.39% | 69,500 | SH |
| 28 | Waters Corporation | WAT | 941848103 | $8.8M | 1.34% | 23,590 | SH |
| 29 | HEICO Corp. | HEI | 422806109 | $6.9M | 1.05% | 19,500 | SH |
| 30 | Fiserv Inc. | FISV | 337738108 | $5.4M | 0.82% | 110,558 | SH |
| 31 | Generac Holdings | GNRC | 368736104 | $4.7M | 0.71% | 16,150 | SH |
| 32 | Pfizer, Inc. | PFE | 717081103 | $4.0M | 0.60% | 165,000 | SH |
| 33 | Microsoft Corp. | MSFT | 594918104 | $3.9M | 0.60% | 10,569 | SH |
| 34 | Ormat Technologies | ORA | 686688102 | $2.8M | 0.43% | 26,100 | SH |
| 35 | Roper Technologies | ROP | 776696106 | $676.8K | 0.10% | 2,000 | SH |
| 36 | Viper Energy Inc | VNOM | 64361Q101 | $326.5K | 0.05% | 7,700 | SH |
| 37 | ATHA Energy Corp. | SASKF | 046824108 | $52.0K | 0.01% | 74,500 | SH |
| 38 | Stallion Uranium Corp | STLNF | 852919208 | $25.4K | 0.00% | 180,000 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-07-09 | $662.3M | 38 | 0000883511-26-000003 |
| 2026-03-31 | 2026-04-08 | $611.2M | 38 | 0000883511-26-000002 |
| 2025-12-31 | 2026-01-09 | $622.2M | 34 | 0000883511-26-000001 |