Avantor, Inc.
US ˙ NYSE ˙ US05352A1007

SecurityAVTR / Avantor, Inc.
InstitutionBoothbay Fund Management, Llc
Latest Disclosed Ownership28,877 shares
Latest Disclosed Value $ 226,396
Boothbay Fund Management, Llc ownership in AVTR / Avantor, Inc.

On May 15, 2026 - Boothbay Fund Management, Llc filed a 13F-HR form disclosing ownership of 28,877 shares of Avantor, Inc. (US:AVTR) valued at $226,396 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 26,670 shares of Avantor, Inc.. This represents a change in shares of 8.28% during the quarter. The current value of the position is $264,513 USD.

Boothbay Fund Management, Llc has a history of taking positions in derivatives of the underlying security (AVTR) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

AVTR / Avantor, Inc. Historical Put/Call Ratio
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 AVANTOR COM 05352A100 28,877 2,207 8.28 226 -25.90 0.0029
2026-02-17 2025-12-31 13F AVANTOR COM 05352A100 26,670 26,670 306 0.0046
2025-11-14 2025-09-30 13F AVANTOR COM 05352A100 0 -15,077 -100.00 0 -100.00
2025-08-14 2025-06-30 13F AVANTOR COM 05352A100 15,077 15,077 203 0.0039
2025-05-15 2025-03-31 13F AVANTOR COM 05352A100 0 -11,225 -100.00 0 -100.00
2025-02-14 2024-12-31 13F AVANTOR COM 05352A100 11,225 -15,054 -57.29 237 -65.24 0.0058
2024-11-14 2024-09-30 13F AVANTOR COM 05352A100 26,279 33 0.13 680 22.12 0.0155
2024-08-14 2024-06-30 13F AVANTOR COM 05352A100 26,246 -173,997 -86.89 556 -89.14 0.0132
2024-05-15 2024-03-31 13F AVANTOR COM 05352A100 200,243 183,549 1,099.49 5,120 1,243.83 0.0986
2024-02-14 2023-12-31 13F AVANTOR COM 05352A100 16,694 16,694 381 0.0097
2023-11-14 2023-09-30 13F AVANTOR COM 05352A100 0 -13,097 -100.00 0 -100.00
2023-08-14 2023-06-30 13F AVANTOR COM 05352A100 13,097 -48,634 -78.78 269 -79.37 0.0059
2023-05-15 2023-03-31 13F AVANTOR COM 05352A100 61,731 -289,027 -82.40 1,305 -82.37 0.0268
2023-02-14 2022-12-31 13F AVANTOR COM 05352A100 350,758 -44,343 -11.22 7,397 -4.48 0.1712
2022-11-14 2022-09-30 13F AVANTOR COM 05352A100 395,101 -11,126 -2.74 7,744 -38.71 0.1933
2022-08-15 2022-06-30 13F AVANTOR COM 05352A100 406,227 132,449 48.38 12,634 36.45 0.3325
2022-05-16 2022-03-31 13F AVANTOR COM 05352A100 273,778 97,755 55.54 9,259 24.82 0.2153
2022-02-14 2021-12-31 13F AVANTOR COM 05352A100 176,023 42,394 31.73 7,418 35.74 0.1745
2021-11-15 2021-09-30 13F AVANTOR COM 05352A100 133,629 -15,688 -10.51 5,465 3.07 0.1512
2021-08-17 2021-06-30 13F/A-1 AVANTOR COM 05352A100 149,317 -69,830 -31.86 5,302 -16.37 0.1703
2021-08-16 2021-06-30 13F AVANTOR COM 05352A100 149,317 -69,830 5,302 0.1668
2021-05-17 2021-03-31 13F AVANTOR COM 05352A100 219,147 152,192 227.30 6,340 236.34 0.2375
2021-02-12 2020-12-31 13F AVANTOR COM 05352A100 66,955 11,847 21.50 1,885 52.14 0.0701
2020-11-16 2020-09-30 13F AVANTOR COM 05352A100 55,108 55,108 1,239 0.0750
2020-08-14 2020-06-30 13F AVANTOR COM 05352A100 0 -22,303 -100.00 0 -100.00
2020-05-15 2020-03-31 13F AVANTOR COM 05352A100 22,303 -5,399 -19.49 279 -44.53 0.0231
2020-02-14 2019-12-31 13F AVANTOR COM 05352A100 27,702 -15,071 -35.23 503 -20.03 0.0438
2019-11-14 2019-09-30 13F Avantor COM 05352A100 42,773 42,773 629 0.0577
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2022-11-14 2022-09-30 13F AVANTOR COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-08-15 2022-06-30 13F AVANTOR COM Call 19,000 591 n/a n/a n/a
2022-02-14 2021-12-31 13F AVANTOR COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F AVANTOR COM Call 5,000 205 n/a n/a n/a
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.