Clean Harbors, Inc.
MX ˙ BMV ˙ US1844961078
SecurityMX:CLH1 / Clean Harbors, Inc.
InstitutionPrelude Capital Management, Llc
Latest Disclosed Ownership14,653 shares
Latest Disclosed Value $ 4,201,455
Prelude Capital Management, Llc reports 9.07% decrease in ownership of CLH1 / Clean Harbors, Inc.

On May 15, 2026 - Prelude Capital Management, Llc filed a 13F-HR form disclosing ownership of 14,653 shares of Clean Harbors, Inc. (MX:CLH1) valued at $4,201,455 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 16,114 shares of Clean Harbors, Inc.. This represents a change in shares of -9.07% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F CLEAN HARBORS COM 184496107 14,653 -1,461 -9.07 4,201 11.20 0.3213
2026-02-17 2025-12-31 13F CLEAN HARBORS COM 184496107 16,114 3,054 23.38 3,778 24.60 0.2780
2025-11-14 2025-09-30 13F CLEAN HARBORS COM 184496107 13,060 48 0.37 3,033 0.80 0.2366
2025-08-14 2025-06-30 13F CLEAN HARBORS COM 184496107 13,012 5,135 65.19 3,008 93.81 0.2925
2025-05-15 2025-03-31 13F CLEAN HARBORS COM 184496107 7,877 253 3.32 1,553 -11.52 0.1180
2025-02-14 2024-12-31 13F CLEAN HARBORS COM 184496107 7,624 -1,137 -12.98 1,755 -17.15 0.1100
2024-11-14 2024-09-30 13F/A-1 CLEAN HARBORS COM 184496107 8,761 -6,442 -42.37 2,118 -38.42 0.1281
2024-11-14 2024-09-30 13F CLEAN HARBORS COM 184496107 8,761 -6,442 2,118 0.0794
2024-08-14 2024-06-30 13F CLEAN HARBORS COM 184496107 15,203 -11,404 -42.86 3,438 -35.81 0.2387
2024-05-15 2024-03-31 13F CLEAN HARBORS COM 184496107 26,607 3,246 13.89 5,356 31.40 0.2811
2024-02-14 2023-12-31 13F CLEAN HARBORS COM 184496107 23,361 6,109 35.41 4,077 41.18 0.2700
2023-11-14 2023-09-30 13F CLEAN HARBORS COM 184496107 17,252 1,227 7.66 2,887 9.61 0.1881
2023-08-14 2023-06-30 13F CLEAN HARBORS COM 184496107 16,025 1,897 13.43 2,635 30.78 0.1715
2023-06-01 2023-03-31 13F/A-1 CLEAN HARBORS COM 184496107 14,128 -3,935 -21.78 2,014 -2.28 0.1206
2023-05-15 2023-03-31 13F CLEAN HARBORS COM 184496107 14,128 -3,935 2,014 0.0655
2023-02-14 2022-12-31 13F CLEAN HARBORS COM 184496107 18,063 10,899 152.14 2,061 161.55 0.1071
2022-11-14 2022-09-30 13F CLEAN HARBORS COM 184496107 7,164 7,164 788 0.0283
2022-08-24 2022-06-30 13F/A-1 CLEAN HARBORS COM 184496107 0 -2,409 -100.00 0 -100.00
2022-08-15 2022-06-30 13F CLEAN HARBORS COM 184496107 0 -2,409 0
2022-05-16 2022-03-31 13F CLEAN HARBORS COM 184496107 2,409 -1,602 -39.94 269 -32.75 0.0077
2022-02-14 2021-12-31 13F CLEAN HARBORS COM 184496107 4,011 4,011 400 0.0103
2021-02-16 2020-12-31 13F CLEAN HARBORS COM 184496107 0 -605 -100.00 0 -100.00
2020-11-16 2020-09-30 13F CLEAN HARBORS COM 184496107 605 -38 -5.91 34 -12.82 0.0016
2020-08-14 2020-06-30 13F CLEAN HARBORS COM 184496107 643 643 39 0.0021
2019-11-14 2019-09-30 13F CLEAN HARBORS COM 184496107 0 -684 -100.00 0 -100.00
2019-08-14 2019-06-30 13F CLEAN HARBORS COM 184496107 684 684 49 0.0024
2019-05-15 2019-03-31 13F CLEAN HARBORS COM 184496107 0 -3,455 -100.00 0 -100.00
2019-02-14 2018-12-31 13F CLEAN HARBORS COM 184496107 3,455 3,455 171 0.0115
2016-11-14 2016-09-30 13F CLEAN HARBORS COM 184496107 0 -7,399 -100.00 0 -100.00
2016-08-15 2016-06-30 13F CLEAN HARBORS COM 184496107 7,399 7,399 12,231.67 386 9,550.00 0.0540
2014-02-14 2013-12-31 13F CLEAN HARBORS COM 184496107 0 -60 -100.00 0 -100.00
2013-11-14 2013-09-30 13F CLEAN HARBORS COM 184496107 60 60 4 0.0006
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.