Pfizer Inc.
CL ˙ SNSE ˙ US7170811035
SecurityCL:PFE / Pfizer Inc.
InstitutionHarbor Advisors LLC
Latest Disclosed Ownership31,962 shares
Latest Disclosed Value $ 897,493
Harbor Advisors LLC ownership in PFE / Pfizer Inc.

On May 7, 2026 - Harbor Advisors LLC filed a 13F-HR form disclosing ownership of 31,962 shares of Pfizer Inc. (CL:PFE) valued at $897,493 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 30, 2026 disclosing 31,962 shares of Pfizer Inc.. This represents a change in shares of 0.00% 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)
2026-05-07 2026-03-31 13F PFIZER COM 717081103 31,962 0 0.00 897 12.83 0.1297
2026-01-30 2025-12-31 13F PFIZER COM 717081103 31,962 0 0.00 796 -2.33 0.1195
2025-11-12 2025-09-30 13F PFIZER COM 717081103 31,962 0 0.00 814 5.17 0.1256
2025-08-13 2025-06-30 13F PFIZER COM 717081103 31,962 0 0.00 775 -4.33 0.1268
2025-05-15 2025-03-31 13F PFIZER COM 717081103 31,962 0 0.00 810 -4.49 0.1406
2025-02-11 2024-12-31 13F PFIZER COM 717081103 31,962 0 0.00 848 -8.33 0.1332
2024-11-14 2024-09-30 13F PFIZER COM 717081103 31,962 0 0.00 925 3.36 0.1548
2024-07-30 2024-06-30 13F PFIZER COM 717081103 31,962 0 0.00 894 0.90 0.1640
2024-05-01 2024-03-31 13F PFIZER COM 717081103 31,962 0 0.00 887 -3.70 0.1629
2024-02-01 2023-12-31 13F PFIZER COM 717081103 31,962 13,000 68.56 920 46.50 0.1759
2023-11-07 2023-09-30 13F PFIZER COM 717081103 18,962 0 0.00 629 -9.64 0.1347
2023-08-15 2023-06-30 13F/A-1 PFIZER COM 717081103 18,962 0 0.00 696 -10.09 0.1478
2023-08-01 2023-06-30 13F PFIZER COM 717081103 18,962 696
2023-05-11 2023-03-31 13F PFIZER COM 717081103 18,962 0 0.00 774 -20.39 0.1810
2023-02-13 2022-12-31 13F PFIZER COM 717081103 18,962 0 0.00 972 16.99 0.2425
2022-11-07 2022-09-30 13F PFIZER COM 717081103 18,962 0 0.00 830 -16.50 0.2233
2022-08-05 2022-06-30 13F PFIZER COM 717081103 18,962 0 0.00 994 1.22 0.2413
2022-05-16 2022-03-31 13F PFIZER COM 717081103 18,962 0 0.00 982 -12.32 0.2013
2022-02-14 2021-12-31 13F PFIZER COM 717081103 18,962 0 0.00 1,120 37.25 0.2083
2021-10-29 2021-09-30 13F PFIZER COM 717081103 18,962 0 0.00 816 9.83 0.1632
2021-08-03 2021-06-30 13F PFIZER COM 717081103 18,962 0 0.00 743 8.15 0.1469
2021-05-04 2021-03-31 13F PFIZER COM 717081103 18,962 0 0.00 687 -1.58 0.1523
2021-02-11 2020-12-31 13F PFIZER COM 717081103 18,962 0 0.00 698 0.29 0.1563
2020-11-09 2020-09-30 13F PFIZER COM 717081103 18,962 0 0.00 696 12.26 0.1636
2020-08-03 2020-06-30 13F PFIZER COM 717081103 18,962 0 0.00 620 0.16 0.1589
2020-05-21 2020-03-31 13F PFIZER COM 717081103 18,962 0 0.00 619 -16.69 0.1878
2020-02-13 2019-12-31 13F PFIZER COM 717081103 18,962 0 0.00 743 9.10 0.2013
2019-11-13 2019-09-30 13F PFIZER COM 717081103 18,962 0 0.00 681 -17.05 0.1949
2019-08-14 2019-06-30 13F PFIZER COM 717081103 18,962 0 0.00 821 1.99 0.2454
2019-05-15 2019-03-31 13F PFIZER COM 717081103 18,962 0 0.00 805 -2.78 0.2595
2019-02-15 2018-12-31 13F PFIZER COM 717081103 18,962 0 0.00 828 -0.96 0.3220
2018-11-14 2018-09-30 13F PFIZER COM 717081103 18,962 0 0.00 836 21.51 0.2596
2018-08-07 2018-06-30 13F PFIZER COM 717081103 18,962 0 0.00 688 2.23 0.2215
2018-05-11 2018-03-31 13F PFIZER COM 717081103 18,962 0 0.00 673 -2.04 0.2266
2018-02-07 2017-12-31 13F PFIZER COM 717081103 18,962 0 0.00 687 1.48 0.2333
2017-10-26 2017-09-30 13F PFIZER COM 717081103 18,962 0 0.00 677 6.28 0.2479
2017-08-14 2017-06-30 13F PFIZER COM 717081103 18,962 0 0.00 637 -1.85 0.2520
2017-05-15 2017-03-31 13F PFIZER COM 717081103 18,962 0 0.00 649 5.36 0.2763
2017-01-30 2016-12-31 13F PFIZER COM 717081103 18,962 18,962 616 0.2954
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.