Montrose Environmental Group, I

Historical 13F Holders

Symbol
ONT
CUSIP
615111101
All holders as of
Q2 2026
Type
Equity
Class
COM
Reported Value, Excluding Options
Total Filings

13D/G Filers

Investors who own more than 5% of a class must file a Schedule 13D or 13G. Each filer's latest filing for 615111101 since 12/18/2024, largest first.

Filer % of Class Filed
FMR LLC 13G
12.7% 9/8/2026
Event 8/31/2026
Bamco Inc /NY/ 13G/A
6.1% 11/14/2025
Event 9/30/2025
Nomura Asset Management International Inc. 13G
6.0% 8/14/2026
Event 6/30/2026
Goldman Sachs Asset Management, L.P. 13G 5.0% 5/11/2026
Event 3/31/2026
Under 5%, checked the "5 percent or less" box, or amended by a later filing (6)
William Blair Investment Management, LLC 13G/A 3.7% 11/12/2025
Event 9/30/2025
Alger Associates, Inc. 13G/A 3.0% 2/14/2025
Event 12/31/2024
Managed Account Advisors LLC 13G/A 2.7% 8/14/2025
Event 6/30/2025
Macquarie Group Ltd 13G/A
0% 2/13/2026
Event 12/31/2025
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 13G/A 0% 10/24/2025
Event 9/30/2025
Vanguard Group Inc 13G/A 0% 3/27/2026
Event 3/13/2026

13F Holders by Quarter

Period Filings Shares, Excl. Options Value, Excl. Options
2026 Q3 4 20.7 k $278 k
2026 Q2 162 38.8 M $809 M
2026 Q1 177 34.0 M $748 M
2025 Q4 194 32.9 M $829 M
2025 Q3 199 32.6 M $895 M
2025 Q2 178 34.4 M $753 M
2025 Q1 184 34.4 M $490 M
2024 Q4 178 33.7 M $623 M
2024 Q3 189 33.3 M $876 M
2024 Q2 184 33.3 M $1.48 B
2024 Q1 178 27.1 M $1.06 B
2023 Q4 167 26.8 M $860 M
2023 Q3 155 26.6 M $778 M
2023 Q2 149 27.1 M $1.13 B
2023 Q1 140 28.0 M $993 M
2022 Q4 144 28.3 M $1.27 B
2022 Q3 133 27.4 M $922 M
2022 Q2 136 26.7 M $901 M
2022 Q1 152 26.2 M $1.39 B
2021 Q4 157 25.6 M $1.80 B
2021 Q3 149 24.4 M $1.51 B
2021 Q2 131 18.7 M $1.00 B
2021 Q1 123 17.8 M $893 M
2020 Q4 112 16.0 M $495 M
2020 Q3 77 15.0 M $356 M