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DUDLEY & SHANLEY, INC.

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13F filer, CIK 883511, PALM BEACH, FL

DUDLEY & SHANLEY, INC. reported $611,236,912 across 37 holdings for the quarter ended 2026-03-31, in a 13F-HR filed 2026-04-08. Its ten largest share positions make up 51.76% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0000883511-26-000002

Period
2026-03-31
Reported value
$611M
Holdings
37
Top 10 weight
51.76%
New
4
Sold out
0

Largest buys vs the previous quarter

SecurityShares changeApprox. value
XYLnew+80,830$9.66M
FASTadded+174,100$8.08M
FSSnew+62,730$6.78M
KAIadded+20,615$6.03M
BMIadded+39,455$6.01M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
WPMreduced-209,220-$27.4M
ADIreduced-29,900-$9.51M
ROPreduced-15,455-$5.47M
APHreduced-37,160-$4.7M
NXEreduced-10,650-$124K

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q1 2026

Share positions as resolved from 13F-HR 0000883511-26-000002, largest first. % of portfolio is the value over $611,236,912, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
WPMWHEATON PRECIOUS METALS CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 1,169,040 shares; 2025Q1: 1,011,010 shares; 2025Q2: 763,475 shares; 2025Q3: 695,665 shares; 2025Q4: 668,605 shares; 2026Q1: 459,385 shares 459,385$60.2M9.85%-209,220Timeline
APHAMPHENOL CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 438,950 shares; 2025Q1: 438,940 shares; 2025Q2: 428,000 shares; 2025Q3: 316,596 shares; 2025Q4: 282,911 shares; 2026Q1: 245,751 shares 245,751$31.1M5.08%-37,160Timeline
SCISERVICE CORP INTLQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 373,053 shares; 2025Q1: 368,393 shares; 2025Q2: 369,033 shares; 2025Q3: 369,433 shares; 2025Q4: 367,633 shares; 2026Q1: 367,633 shares 367,633$30.3M4.96%0Timeline
ADIANALOG DEVICES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 122,656 shares; 2025Q1: 122,756 shares; 2025Q2: 122,976 shares; 2025Q3: 124,996 shares; 2025Q4: 125,021 shares; 2026Q1: 95,121 shares 95,121$30.3M4.95%-29,900Timeline
AMEAMETEK INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 139,316 shares; 2025Q1: 139,426 shares; 2025Q2: 139,686 shares; 2025Q3: 139,786 shares; 2025Q4: 139,796 shares; 2026Q1: 139,746 shares 139,746$30M4.9%-50Timeline
VVISA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 97,636 shares; 2025Q1: 97,246 shares; 2025Q2: 97,211 shares; 2025Q3: 97,181 shares; 2025Q4: 97,216 shares; 2026Q1: 97,166 shares 97,166$29.4M4.8%-50Timeline
AONAON PLCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 93,827 shares; 2025Q1: 88,637 shares; 2025Q2: 88,632 shares; 2025Q3: 88,732 shares; 2025Q4: 88,782 shares; 2026Q1: 88,782 shares 88,782$28.7M4.69%0Timeline
ECLECOLAB INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 104,853 shares; 2025Q1: 104,863 shares; 2025Q2: 104,983 shares; 2025Q3: 104,983 shares; 2025Q4: 105,058 shares; 2026Q1: 105,008 shares 105,008$27.9M4.57%-50Timeline
ROLROLLINS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 455,750 shares; 2025Q1: 456,100 shares; 2025Q2: 456,900 shares; 2025Q3: 455,650 shares; 2025Q4: 455,730 shares; 2026Q1: 455,730 shares 455,730$24.3M3.98%0Timeline
FERGFERGUSON ENTERPRISES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 109,375 shares; 2025Q1: 101,125 shares; 2025Q2: 75,500 shares; 2025Q3: 75,500 shares; 2025Q4: 104,175 shares; 2026Q1: 104,175 shares 104,175$24.3M3.98%0Timeline
AWKAMERICAN WTR WKS CO INC NEWQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 160,894 shares; 2025Q1: 161,014 shares; 2025Q2: 161,304 shares; 2025Q3: 169,159 shares; 2025Q4: 169,044 shares; 2026Q1: 169,044 shares 169,044$23M3.76%0Timeline
DCIDONALDSON INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 268,750 shares; 2025Q1: 244,965 shares; 2025Q2: 209,185 shares; 2025Q3: 270,585 shares; 2025Q4: 270,405 shares; 2026Q1: 270,405 shares 270,405$22.9M3.75%0Timeline
SCHWCHARLES SCHWAB CORP (THE)Quarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 240,383 shares; 2025Q1: 240,563 shares; 2025Q2: 240,963 shares; 2025Q3: 240,863 shares; 2025Q4: 240,933 shares; 2026Q1: 240,933 shares 240,933$22.6M3.7%0Timeline
KAIKADANT INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 32,500 shares; 2025Q1: 32,530 shares; 2025Q2: 55,175 shares; 2025Q3: 55,175 shares; 2025Q4: 55,120 shares; 2026Q1: 75,735 shares 75,735$22.1M3.62%+20,615Timeline
DHRDANAHER CORP DELQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 109,257 shares; 2025Q1: 109,342 shares; 2025Q2: 109,552 shares; 2025Q3: 114,941 shares; 2025Q4: 114,881 shares; 2026Q1: 114,881 shares 114,881$21.8M3.56%0Timeline
WSOWATSCO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 25,403 shares; 2025Q1: 25,428 shares; 2025Q2: 39,833 shares; 2025Q3: 39,370 shares; 2025Q4: 55,692 shares; 2026Q1: 55,692 shares 55,692$20.3M3.31%0Timeline
ALSNALLISON TRANSMISSION HLDGS IQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 164,097 shares; 2025Q1: 164,247 shares; 2025Q2: 164,547 shares; 2025Q3: 164,547 shares; 2025Q4: 164,597 shares; 2026Q1: 164,597 shares 164,597$19.3M3.15%0Timeline
BMIBADGER METER INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: 82,695 shares; 2026Q1: 122,150 shares 122,150$18.6M3.04%+39,455Timeline
KRNTKORNIT DIGITAL LTDQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 272,025 shares; 2025Q1: 321,150 shares; 2025Q2: 637,300 shares; 2025Q3: 1,258,895 shares; 2025Q4: 901,960 shares; 2026Q1: 1,254,615 shares 1,254,615$18.4M3.01%+352,655Timeline
RYANRYAN SPECIALTY HOLDINGS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 461,381 shares; 2025Q1: 461,381 shares; 2025Q2: 462,071 shares; 2025Q3: 461,921 shares; 2025Q4: 477,671 shares; 2026Q1: 480,021 shares 480,021$16.2M2.65%+2,350Timeline
NXENEXGEN ENERGY LTDQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 1,236,500 shares; 2025Q1: 1,236,500 shares; 2025Q2: 1,237,000 shares; 2025Q3: 1,235,150 shares; 2025Q4: 1,235,150 shares; 2026Q1: 1,224,500 shares 1,224,500$14.2M2.32%-10,650Timeline
PGRPROGRESSIVE CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 84,460 shares; 2025Q1: 84,480 shares; 2025Q2: 64,255 shares; 2025Q3: 64,255 shares; 2025Q4: 66,280 shares; 2026Q1: 66,280 shares 66,280$13.1M2.15%0Timeline
XYLXYLEM INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 80,830 shares 80,830$9.66M1.58%newTimeline
FASTFASTENAL COQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: 7,150 shares; 2026Q1: 181,250 shares 181,250$8.41M1.38%+174,100Timeline
FISVFISERV INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 176,623 shares; 2025Q1: 156,474 shares; 2025Q2: 169,344 shares; 2025Q3: 174,921 shares; 2025Q4: 143,923 shares; 2026Q1: 143,923 shares 143,923$8.03M1.31%0Timeline
FSSFEDERAL SIGNAL CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 62,730 shares 62,730$6.78M1.11%newTimeline
AAGILENT TECHNOLOGIES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 49,200 shares; 2025Q1: 49,200 shares; 2025Q2: 55,200 shares; 2025Q3: 55,200 shares; 2025Q4: 55,200 shares; 2026Q1: 55,200 shares 55,200$6.29M1.03%0Timeline
HEIHEICO CORP NEWQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 19,550 shares; 2025Q1: 19,550 shares; 2025Q2: 19,550 shares; 2025Q3: 19,500 shares; 2025Q4: 19,500 shares; 2026Q1: 19,500 shares 19,500$5.35M0.87%0Timeline
MSFTMICROSOFT CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 11,554 shares; 2025Q1: 10,854 shares; 2025Q2: 10,854 shares; 2025Q3: 10,854 shares; 2025Q4: 10,569 shares; 2026Q1: 10,569 shares 10,569$3.91M0.64%0Timeline
GNRCGENERAC HLDGS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 19,650 shares; 2025Q1: 19,650 shares; 2025Q2: 19,650 shares; 2025Q3: 19,650 shares; 2025Q4: 19,650 shares; 2026Q1: 19,650 shares 19,650$3.84M0.63%0Timeline
WATWATERS CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 11,720 shares 11,720$3.49M0.57%newTimeline
ORAORMAT TECHNOLOGIES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 30,900 shares; 2025Q1: 30,000 shares; 2025Q2: 30,000 shares; 2025Q3: 30,200 shares; 2025Q4: 28,000 shares; 2026Q1: 28,000 shares 28,000$3.13M0.51%0Timeline
PHOINVESCO EXCHANGE TRADED FD TQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 32,780 shares; 2025Q1: 32,780 shares; 2025Q2: 32,780 shares; 2025Q3: 32,780 shares; 2025Q4: 32,780 shares; 2026Q1: 32,780 shares 32,780$2.19M0.36%0Timeline
ROPROPER TECHNOLOGIES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 2,550 shares; 2025Q1: 2,550 shares; 2025Q2: 2,550 shares; 2025Q3: 2,550 shares; 2025Q4: 17,455 shares; 2026Q1: 2,000 shares 2,000$708K0.12%-15,455Timeline
VNOMVIPER ENERGY INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: 7,700 shares; 2026Q1: 7,700 shares 7,700$362K0.06%0Timeline
STLNFSTALLION URANIUM CORP COM NEWQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 30,000 shares; 2025Q4: 85,000 shares; 2026Q1: 180,000 shares 180,000$60.6K0.01%+95,000Timeline
SASKFATHA ENERGY CORP (CANADA)Quarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: restricted; 2024Q4: 19,000 shares; 2025Q1: 19,000 shares; 2025Q2: 19,000 shares; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 74,500 shares 74,500$43.8K0.01%newTimeline

How Q1 2026 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0000883511-26-000002 base2026-04-08acceptance time not in the bulk data set