Cabaletta Bio, Inc.
US ˙ NasdaqGS ˙ US12674W1099

SecurityCABA / Cabaletta Bio, Inc.
InstitutionFred Alger Management, Llc
Latest Disclosed Ownership23,157 shares
Latest Disclosed Value $ 62,292
Fred Alger Management, Llc reports 17.36% decrease in ownership of CABA / Cabaletta Bio, Inc.

On May 15, 2026 - Fred Alger Management, Llc filed a 13F-HR form disclosing ownership of 23,157 shares of Cabaletta Bio, Inc. (US:CABA) valued at $62,292 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 28,021 shares of Cabaletta Bio, Inc.. This represents a change in shares of -17.36% during the quarter. The current value of the position is $74,913 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)
2026-05-15 2026-03-31 13F Cabaletta Bio Equity 12674W109 23,157 -4,864 -17.36 62 1.64 0.0002
2026-02-17 2025-12-31 13F Cabaletta Bio Equity 12674W109 28,021 -31,792 -53.15 61 -56.12 0.0002
2025-11-14 2025-09-30 13F Cabaletta Bio Equity 12674W109 59,813 0 0.00 140 54.44 0.0005
2025-08-14 2025-06-30 13F Cabaletta Bio Equity 12674W109 59,813 -417,397 -87.47 91 -86.36 0.0004
2025-05-16 2025-03-31 13F Cabaletta Bio Equity 12674W109 477,210 -1,839,014 -79.40 661 -87.45 0.0038
2025-02-14 2024-12-31 13F Cabaletta Bio Equity 12674W109 2,316,224 -1,803,170 -43.77 5,258 -72.96 0.0251
2024-11-14 2024-09-30 13F CABALETTA BIO Common 12674W109 4,119,394 1,596,512 63.28 19,444 3.03 0.0942
2024-08-14 2024-06-30 13F CABALETTA BIO Common 12674W109 2,522,882 -587,432 -18.89 18,871 -64.44 0.0917
2024-05-15 2024-03-31 13F CABALETTA BIO Common 12674W109 3,110,314 -216,818 -6.52 53,062 -29.74 0.2631
2024-02-14 2023-12-31 13F CABALETTA BIO Common 12674W109 3,327,132 -932,323 -21.89 75,526 16.50 0.4075
2023-11-14 2023-09-30 13F CABALETTA BIO Common 12674W109 4,259,455 -313,431 -6.85 64,829 9.81 0.3437
2023-11-14 2023-09-30 13F CABALETTA BIO Common 12674W109 4,259,455 64,829
2023-08-14 2023-06-30 13F CABALETTA BIO Common 12674W109 4,572,886 557,576 13.89 59,036 77.78 0.3016
2023-05-16 2023-03-31 13F/A-1 CABALETTA BIO Common 12674W109 4,015,310 3,279,361 445.60 33,207 387.82 0.1776
2023-05-15 2023-03-31 13F CABALETTA BIO Common 12674W109 4,015,310 3,279,361 33,207 0.1647
2023-02-14 2022-12-31 13F CABALETTA BIO Common 12674W109 735,949 735,949 6,808 0.0369
2022-02-14 2021-12-31 13F CABALETTA BIO Common 12674W109 0 -214,721 -100.00 0 -100.00
2021-11-15 2021-09-30 13F CABALETTA BIO Common 12674W109 214,721 214,721 2,611 0.0062
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.