Acumen Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US00509G2093

SecurityABOS / Acumen Pharmaceuticals, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership4,486 shares
Latest Disclosed Value $ 10,587
Citigroup Inc ownership in ABOS / Acumen Pharmaceuticals, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 4,486 shares of Acumen Pharmaceuticals, Inc. (US:ABOS) valued at $10,587 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 0 shares of Acumen Pharmaceuticals, Inc.. The current value of the position is $10,251 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 ACUMEN PHARMACEUTICALS COM 00509G209 4,486 4,486 11 0.0000
2026-02-13 2025-12-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 0 -151 -100.00 0 0.0000
2025-11-10 2025-09-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 151 -2,964 -95.15 0 -100.00 0.0000
2025-08-11 2025-06-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 3,115 -26,721 -89.56 4 -90.62 0.0000
2025-05-12 2025-03-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 29,836 -50,509 -62.87 33 -76.81 0.0000
2025-02-12 2024-12-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 80,345 49,753 162.63 138 84.00 0.0001
2024-11-12 2024-09-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 30,592 21,177 224.93 76 240.91 0.0000
2024-08-12 2024-06-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 9,415 -125,979 -93.05 23 -95.99 0.0000
2024-05-10 2024-03-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 135,394 -12,417 -8.40 548 -3.35 0.0004
2024-02-09 2023-12-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 147,811 109,313 283.94 568 256.60 0.0004
2023-12-06 2023-09-30 13F/A-1 ACUMEN PHARMACEUTICALS COM 00509G209 38,498 37,801 5,423.39 160 5,200.00 0.0001
2023-11-09 2023-09-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 38,498 37,801 160 0.0000
2023-08-10 2023-06-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 697 -40,680 -98.32 3 -98.20 0.0000
2023-05-11 2023-03-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 41,377 -4,197 -9.21 168 -32.11 0.0001
2023-02-09 2022-12-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 45,574 37,258 448.03 246 196.39 0.0002
2022-11-10 2022-09-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 8,316 7,385 793.23 83 1,975.00 0.0001
2022-08-10 2022-06-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 931 -2,762 -74.79 4 -71.43 0.0000
2022-05-12 2022-03-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 3,693 -198 -5.09 14 -46.15 0.0000
2022-02-10 2021-12-31 13F ACUMEN PHARMACEUTICALS COM 00509G209 3,891 2,797 255.67 26 62.50 0.0000
2021-11-10 2021-09-30 13F ACUMEN PHARMACEUTICALS COM 00509G209 1,094 1,094 16 0.0000
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.