Form 13-F position report

CABALETTA BIO INC

Reported by FRED ALGER MANAGEMENT LLC

Company profile Manager portfolio Source filing
CABA CUSIP 12674W109 Manager CIK 0000003520
Latest reported change

Reported 59,813 shares, unchanged from the prior quarter.

Reported value 53.9%; share count 0.0% vs. the prior quarter.

Unchanged
% of reported 13F value < 0.01% This manager · Q3 2025
Shares 59,813 Quarter-end amount reported
Reported value $139,962 Fair value at quarter end
Consecutive quarters held 12 Through Q3 2025

Reported position value by quarter

Reported position value by quarter

Each bar is a Form 13-F quarter-end snapshot. It does not show trades made within the quarter.

Manager history

Quarterly position history

How this manager's reported quarter-end position changed over time.

17 quarters
Quarter Activity Shares Change % of reported 13F Reported value Filed
Q2 2026 Reduced 14,033 -9,124 (-39.4%) < 0.01% $43,643 2026-08-14
Q1 2026 Reduced 23,157 -4,864 (-17.4%) < 0.01% $62,292 2026-05-15
Q4 2025 Reduced 28,021 -31,792 (-53.2%) < 0.01% $61,366 2026-02-17
Q3 2025 Unchanged 59,813 0 (0.0%) < 0.01% $139,962 2025-11-14
Q2 2025 Reduced 59,813 -417,397 (-87.5%) < 0.01% $90,916 2025-08-14
Q1 2025 Reduced 477,210 -1,839,014 (-79.4%) < 0.01% $660,936 2025-05-16
Q4 2024 Reduced 2,316,224 -1,803,170 (-43.8%) 0.03% $5,257,828 2025-02-14
Q3 2024 Added 4,119,394 +1,596,512 (63.3%) 0.09% $19,443,540 2024-11-14
Q2 2024 Reduced 2,522,882 -587,432 (-18.9%) 0.09% $18,871,157 2024-08-14
Q1 2024 Reduced 3,110,314 -216,818 (-6.5%) 0.26% $53,061,957 2024-05-15
Q4 2023 Reduced 3,327,132 -932,323 (-21.9%) 0.41% $75,525,896 2024-02-14
Q3 2023 Reduced 4,259,455 -313,431 (-6.9%) 0.37% $64,828,905 2023-11-14
Q2 2023 Added 4,572,886 +557,576 (13.9%) 0.3% $59,035,958 2023-08-14
Q1 2023 Added 4,015,310 +3,279,361 (445.6%) 0.18% $33,206,614 2023-05-15
Q4 2022 New 735,949 +735,949 (0.0%) 0.04% $6,807,528 2023-02-14
Q4 2021 Reduced 0 -214,721 (-100.0%) 0 $0 2022-02-14
Q3 2021 New 214,721 +214,721 (0.0%) < 0.01% $2,611,000 2021-11-15
Institutional context

Who else reported the position

95 managers reported CABALETTA BIO INC for Q3 2025.

Manager Activity Shares Change % of reported 13F Reported value Tenure
Bain Capital Life Sciences Investors LLC Unchanged 9,677,125 0 1.5% $22,644,473 10 qtrs
ADAGE CAPITAL PARTNERS GP L L C Unchanged 8,829,758 0 0.03% $20,661,634 24 qtrs
JENNISON ASSOCIATES LLC Added 8,497,537 +2,477,370 0.01% $19,884,236 11 qtrs
T Rowe Price Investment Management Inc Added 8,362,489 +1,568,701 0.01% $19,569,000 8 qtrs
Cormorant Asset Management LP Unchanged 5,000,000 0 0.81% $11,700,000 2 qtrs
VANGUARD GROUP INC Added 4,190,759 +740,032 < 0.01% $9,806,376 24 qtrs
Woodline Partners LP Added 2,135,348 +916,884 0.02% $4,996,714 2 qtrs
HEIGHTS CAPITAL MANAGEMENT INC Reduced 2,084,202 -1,059,904 1.39% $4,877,033 2 qtrs
BlackRock Inc Added 1,620,872 +650,271 < 0.01% $3,792,840 5 qtrs
SUPERSTRING CAPITAL MANAGEMENT LP Added 1,544,525 +483,761 3.56% $3,614,189 7 qtrs
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Filing details and methodology As reported
Report period
September 30, 2025
Filed
November 14, 2025
Filing type
13F-HR
Position type
Equity

Voting authority reported

Sole
59,813
Shared
0
None
0

“None” means the manager reported no voting authority for those shares on non-routine matters. It does not disclose why and is not evidence of securities lending.

Form 13-F is a delayed quarter-end snapshot of disclosed long Section 13(f) securities. It can be filed up to 45 days after quarter end, excludes short positions and most non-U.S. securities, and does not reveal intra-quarter trading. For options, reported shares and value describe the underlying-share exposure; strike, expiry, premium, and written positions are not disclosed.