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Clean Harbors Inc

CLH

Clean Harbors Inc

Clean Harbors Inc historical holders

total: 4

Lone Pine Capital Clean Harbors Inc transactions over time

Total transactions:
2
New positions:
1
Added:
1
Held since:
2025 Q4
Held for:
2 quarters
Latest activity:
2026 Q1
Stephen Mandel has been an institutional investor in Clean Harbors Inc (CLH) since 2025 Q4. According to 2026 Q1 report, Stephen Mandel holds 1,754,950 shares with a market value of roughly $503.20M representing 4.01% of their equity portfolio. The fund/company first acquired CLH in 2025 Q4, initially purchasing about 1.38M shares. Since the initial investment, Lone Pine Capital has made 1 more transaction in this position.

Does Stephen Mandel still hold CLH?

Yes, Stephen Mandel continues to hold Clean Harbors Inc (CLH). According to their 2026 Q1 report, they maintain a position of 1,754,950 shares valued at approximately $503.20M, representing 4.01% of their equity portfolio.

When did Stephen Mandel first invest in CLH?

Stephen Mandel first invested in Clean Harbors Inc (CLH) in 2025 Q4 at the reported quarter-end price of $234.48 per share, acquiring 1,378,125 shares in their initial purchase.

What is Stephen Mandel's average cost basis for CLH?

Based on historical transaction data, Stephen Mandel's estimated cost basis for Clean Harbors Inc (CLH) is approximately $245.70 per share. This represents their average reported price* across all buy transactions.

Estimated cost basis*

Weighted AVG buy price:
$245.70

CLH transactions history by Lone Pine Capital

2 results
Period % of
portfolio
Shares
held after*
Reported
price*
Value* % (shares)
of activity
% change
to portfolio
2026 Q1
4.01%
1,754,950
$286.73
$503,196,814
+27.34% (+376,825)
+0.86%
2025 Q4
2.37%
1,378,125
$234.48
$323,142,750
new
+2.37%
* Shares, change to shares, sold shares, shares held after: split-adjusted.
* Reported price: this doesn't represent the actual buy or sell price. It is the split-adjusted price of the security as of the last day of the reported period.
If the security is completely sold out, we show the reported split-adjusted price prior to the actual period.
* Estimated cost basis: based on "Reported price*" (not earlier than 2013 Q2). Calculation starts from the latest "new buy" activity to the latest "close out" activity (if any).
* Value or Price: If the security is completely sold out, we show the reported value (or price) prior to the actual period.
* New buy or own: this means there is no earlier reporting (for us or in general). So we can't know if the actual purchase of the security happened at the reported period or earlier.