Prime Medicine, Inc.

SecurityPRME / Prime Medicine, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership47,232 shares
Latest Disclosed Value $ 164,368
Citigroup Inc reports 7.80% decrease in ownership of PRME / Prime Medicine, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 47,232 shares of Prime Medicine, Inc. (US:PRME) valued at $164,367 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 51,229 shares of Prime Medicine, Inc.. This represents a change in shares of -7.80% during the quarter. The current value of the position is $163,895 USD.

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)
2026-05-11 2026-03-31 13F PRIME MEDICINE COM 74168J101 47,232 -3,997 -7.80 164 -7.34 0.0001
2026-02-13 2025-12-31 13F PRIME MEDICINE COM 74168J101 51,229 46,078 894.54 178 532.14 0.0001
2025-11-10 2025-09-30 13F PRIME MEDICINE COM 74168J101 5,151 -29,608 -85.18 29 -67.06 0.0000
2025-08-11 2025-06-30 13F PRIME MEDICINE COM 74168J101 34,759 -7,543 -17.83 86 1.19 0.0000
2025-05-12 2025-03-31 13F PRIME MEDICINE COM 74168J101 42,302 -5,129 -10.81 84 -39.13 0.0000
2025-02-12 2024-12-31 13F PRIME MEDICINE COM 74168J101 47,431 -640 -1.33 138 -25.81 0.0001
2024-11-12 2024-09-30 13F PRIME MEDICINE COM 74168J101 48,071 30,560 174.52 186 106.67 0.0001
2024-08-12 2024-06-30 13F PRIME MEDICINE COM 74168J101 17,511 -26,459 -60.18 90 -70.68 0.0001
2024-05-10 2024-03-31 13F PRIME MEDICINE COM 74168J101 43,970 33,035 302.10 308 219.79 0.0002
2024-02-09 2023-12-31 13F PRIME MEDICINE COM 74168J101 10,935 -45,258 -80.54 97 -82.09 0.0001
2023-12-06 2023-09-30 13F/A-1 PRIME MEDICINE COM 74168J101 56,193 42,032 296.82 536 158.94 0.0004
2023-11-09 2023-09-30 13F PRIME MEDICINE COM 74168J101 56,193 536
2023-08-10 2023-06-30 13F PRIME MEDICINE COM 74168J101 14,161 5,302 59.85 207 91.67 0.0001
2023-05-11 2023-03-31 13F PRIME MEDICINE COM 74168J101 8,859 5,272 146.98 109 63.64 0.0001
2023-02-09 2022-12-31 13F PRIME MEDICINE COM 74168J101 3,587 3,587 67 0.0001
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.