Longleaf Partners AVTR trades
Mason Hawkins
Mason Hawkins Avantor Inc stake
total: 53
Trades details
- Total transactions:
- 3
- New positions:
- 1
- Added:
- 1
- Reduced:
- 1
- Held since:
- 2025 Q3
- Held for:
- 4 quarters
- Latest activity:
- 2026 Q2
According to 2026 Q2 report, Mason Hawkins holds 4,410,842 Avantor Inc (AVTR) shares with a market value of roughly $43.67M accounting for 4.16% of the overall portfolio. To date, the estimated cost basis is nearly $11.79 for "buy" trades and estimated average "sell" price is $11.46. Longleaf Partners first purchased AVTR in 2025 Q3, initially acquiring about 3.64M shares. Since the initial investment in Avantor Inc (AVTR), Longleaf Partners has made 2 more transactions.
When did Mason Hawkins buy Avantor Inc (AVTR)?
Mason Hawkins first invested in Avantor Inc (AVTR) in 2025 Q3 at the reported quarter-end price of $12.48 per share.
What's the cost basis of Longleaf Partners's AVTR stake?
The estimated cost basis for Avantor Inc (AVTR) stake is around $11.79 per share. This represents their average reported price* across all buy transactions
Estimated cost basis*
- Weighted AVG buy price:
- $11.79
- Weighted AVG sell price:
- $11.46
Mason Hawkins's historical trades in Avantor Inc
3 results
| Period |
% of portfolio |
Shares held after* |
Reported price* |
Value* |
% (shares) of activity |
% change to portfolio |
|---|---|---|---|---|---|---|
|
2026 Q2
|
4.16%
|
4,410,842
|
$9.90
|
$43,667,336
|
+42.91% (+1,324,406)
|
+1.25%
|
|
2025 Q4
|
3.22%
|
3,086,436
|
$11.46
|
$35,370,557
|
-15.20% (-553,218)
|
-0.56%
|
|
2025 Q3
|
4.01%
|
3,639,654
|
$12.48
|
$45,422,882
|
new
|
+4.01%
|
* 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.
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.