DUDLEY & SHANLEY, INC.

Fundamental concentrated ★Highest signal CIK 883511
League rank
#852
in Fundamental concentrated · #6987 overall
Long book
$611.2M
Q1 2026
Positions
37
Top-10 weight
52%
concentration
Last quarter
+5.5%
SPY +14.8%
Turnover
11%
of book per quarter

Strategy in plain words

auto-generated from filings

DUDLEY & SHANLEY, INC. is a concentrated fundamental stock-picker, running a $611.2M US long book across 37 positions.

The portfolio is concentrated: the top 10 names carry 52% of the portfolio. Turnover is modest: positions are typically held for years. Current anchor positions: WHEATON PRECIOUS METALS CORP, AMPHENOL CORP-CL A, SERVICE CORP INTERNATIONAL, ANALOG DEVICES INC, AMETEK INC.

Over the last 9 quarters its long book ran on average 1.8pp per quarter behind the S&P 500, beating the index in 3 of 9 quarters. We rate its filings highest-signal: new buys here are worth attention.

Implied long-book return vs S&P 500

methodology: positions priced quarterly, no shorts/options
Fund long book S&P 500
Q1 2024
-1.0%
Q2 2024
+10.4%
Q3 2024
-1.6%
Q4 2024
+3.9%
Q1 2025
+4.9%
Q2 2025
+2.6%
Q3 2025
+0.4%
Q4 2025
-1.1%
Q1 2026
+5.5%

Sector allocation

Technology
22%
Industrials
18%
Services media
15%
Financials
13%
Materials
12%
Consumer discretionary
9%
Other
5%
Utilities
4%

Long book by quarter

$592.6M
Q1 2024
$581.9M
Q2 2024
$639.7M
Q3 2024
$647.6M
Q4 2024
$635.1M
Q1 2025
$636.8M
Q2 2025
$621.5M
Q3 2025
$622.2M
Q4 2025
$611.2M
Q1 2026

What does DUDLEY & own?

Q1 2026 13F
CompanySectorSharesValue% of bookChange
WPM WHEATON PRECIOUS METALS CORPMaterials459.4K$60.2M9.8%-31.3%
APH AMPHENOL CORP-CL ATechnology245.8K$31.1M5.1%-13.1%
SCI SERVICE CORP INTERNATIONALServices media367.6K$30.3M5.0%Held
ADI ANALOG DEVICES INCTechnology95.1K$30.3M5.0%-23.9%
AME AMETEK INCTechnology139.7K$30.0M4.9%0.0%
V VISA INC-CLASS A SHARESServices media97.2K$29.4M4.8%-0.1%
AON AON PLC-CLASS AFinancials88.8K$28.7M4.7%Held
ECL ECOLAB INCOther105.0K$27.9M4.6%0.0%
ROL ROLLINS INCServices media455.7K$24.3M4.0%Held
FERG FERGUSON ENTERPRISES INCConsumer discretionary104.2K$24.3M4.0%Held
AWK AMERICAN WATER WORKS CO INCUtilities169.0K$23.0M3.8%Held
DCI DONALDSON CO INCIndustrials270.4K$22.9M3.8%Held
SCHW SCHWAB (CHARLES) CORPFinancials240.9K$22.6M3.7%Held
KAI KADANT INCIndustrials75.7K$22.1M3.6%+37.4%
DHR DANAHER CORPTechnology114.9K$21.8M3.6%Held
WSO WATSCO INCConsumer discretionary55.7K$20.3M3.3%Held
ALSN ALLISON TRANSMISSION HOLDINGIndustrials164.6K$19.3M3.2%Held
BMI BADGER METER INCTechnology122.2K$18.6M3.0%+47.7%
KRNT KORNIT DIGITAL LTDIndustrials1.3M$18.4M3.0%+39.1%
RYAN RYAN SPECIALTY HOLDINGS INCFinancials480.0K$16.2M2.6%+0.5%
NXE NEXGEN ENERGY LTDMaterials1.2M$14.2M2.3%-0.9%
PGR PROGRESSIVE CORPFinancials66.3K$13.1M2.1%Held
XYL XYLEM INCIndustrials80.8K$9.7M1.6%New
FAST FASTENAL COConsumer discretionary181.3K$8.4M1.4%+2435.0%
FISV FISERV INCServices media143.9K$8.0M1.3%Held
FSS FEDERAL SIGNAL CORPIndustrials62.7K$6.8M1.1%New
A AGILENT TECHNOLOGIES INCHealthcare55.2K$6.3M1.0%Held
HEI HEICO CORPIndustrials19.5K$5.3M0.9%Held
MSFT MICROSOFT CORPTechnology10.6K$3.9M0.6%Held
GNRC GENERAC HOLDINGS INCIndustrials19.6K$3.8M0.6%Held
WAT WATERS CORPHealthcare11.7K$3.5M0.6%New
ORA ORMAT TECHNOLOGIES INCUtilities28.0K$3.1M0.5%Held
ROP ROPER TECHNOLOGIES INCTechnology2.0K$708K0.1%-88.5%
VNOM VIPER ENERGY INC-CL AEnergy7.7K$362K0.1%Held
STLNF STALLION URANIUM CORP180.0K$61K0.0%+111.8%
SASKF ATHA ENERGY CORP74.5K$44K0.0%New

13F filing history

PeriodFormFiledEntriesReported valueFlagsSource
Q1 202613F-HRApr 8, 202638$611.2M canonicalSEC ↗
Q4 202513F-HRJan 9, 202634$622.2M canonicalSEC ↗
Q3 202513F-HROct 8, 202533$621.5M canonicalSEC ↗
Q2 202513F-HRJul 9, 202537$636.8M canonicalSEC ↗
Q1 202513F-HRApr 9, 202537$635.1M canonicalSEC ↗
Q4 202413F-HRJan 3, 202538$647.6M canonicalSEC ↗
Q3 202413F-HRDec 23, 202437$639.7M canonicalSEC ↗
Q2 202413F-HRJul 9, 202437$581.9M canonicalSEC ↗
Q1 202413F-HRApr 19, 202437$592.6M canonicalSEC ↗