Form 13-F position report

SPERO THERAPEUTICS INC

Reported by MORGAN STANLEY

Company profile Manager portfolio Source filing
SPRO CUSIP 84833T103 Manager CIK 0000895421
Latest reported change

Reported 17,077 shares, down 2,177 (11.3%) from the prior quarter.

Reported value -22.3%; share count -11.3% vs. the prior quarter.

Reduced
% of reported 13F value < 0.01% This manager · Q4 2022
Shares 17,077 Quarter-end amount reported
Reported value $29,543 Fair value at quarter end
Consecutive quarters held 21 Through Q4 2022

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.

20 quarters
Quarter Activity Shares Change % of reported 13F Reported value Filed
Q2 2026 Reduced 914 -3,638 (-79.9%) < 0.01% $2,020 2026-08-13
Q1 2026 Added 4,552 +4,239 (1354.3%) < 0.01% $10,651 2026-05-15
Q4 2025 Reduced 313 -43,065 (-99.3%) < 0.01% $729 2026-02-13
Q3 2025 Added 43,378 +34,157 (370.4%) < 0.01% $81,550 2025-11-14
Q2 2025 Added 9,221 +2,250 (32.3%) < 0.01% $26,741 2025-08-15
Q1 2025 Unchanged 6,971 0 (0.0%) < 0.01% $5,019 2025-05-15
Q4 2024 Unchanged 6,971 0 (0.0%) < 0.01% $7,180 2025-02-14
Q3 2024 Unchanged 6,971 0 (0.0%) < 0.01% $9,341 2024-11-14
Q2 2024 Reduced 6,971 -928 (-11.7%) < 0.01% $9,062 2024-08-14
Q1 2024 Reduced 7,899 -4,136 (-34.4%) < 0.01% $13,586 2024-05-15
Q4 2023 Added 12,035 +3,047 (33.9%) < 0.01% $17,691 2024-02-13
Q3 2023 Reduced 8,988 -542 (-5.7%) < 0.01% $10,875 2023-11-15
Q2 2023 Reduced 9,530 -5,700 (-37.4%) < 0.01% $13,819 2023-08-14
Q1 2023 Reduced 15,230 -1,847 (-10.8%) < 0.01% $22,084 2023-05-15
Q4 2022 Reduced 17,077 -2,177 (-11.3%) < 0.01% $29,543 2023-02-14
Q3 2022 Reduced 19,254 -174,355 (-90.1%) < 0.01% $38,000 2022-11-14
Q2 2022 Added 193,609 +120,613 (165.2%) < 0.01% $143,000 2022-08-15
Q1 2022 Added 72,996 +22,584 (44.8%) < 0.01% $635,000 2022-05-13
Q4 2021 Reduced 50,412 -6,089 (-10.8%) < 0.01% $807,000 2022-02-14
Q3 2021 Reduced 56,501 -13,271 (-19.0%) < 0.01% $1,041,000 2021-11-15
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Institutional context

Who else reported the position

81 managers reported SPERO THERAPEUTICS INC for Q4 2022.

Manager Activity Shares Change % of reported 13F Reported value Tenure
Anson Funds Management LP Added 3,019,608 +1,545,736 0.86% $5,223,922 2 qtrs
Atlas Venture Associates IX LLC Unchanged 1,376,968 0 11.85% $2,382,155 21 qtrs
AWM Investment Company Inc Reduced 1,300,400 -1,000,000 0.32% $2,249,692 21 qtrs
VANGUARD GROUP INC Added 1,054,388 +665 < 0.01% $1,824,091 21 qtrs
Atlas Venture Life Science Advisors LLC Unchanged 1,031,160 0 0.21% $1,783,907 5 qtrs
Alphabet Inc Unchanged 889,979 0 0.09% $1,539,664 21 qtrs
MILLENNIUM MANAGEMENT LLC Added 876,398 +188,002 < 0.01% $1,516,000 4 qtrs
Murchinson Ltd Unchanged 762,700 0 0.17% $1,319,471 2 qtrs
Rock Springs Capital Management LP Reduced 669,533 -101,177 0.03% $1,158,292 21 qtrs
BlackRock Inc Reduced 488,083 -203,646 < 0.01% $844,383 21 qtrs
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Filing details and methodology As reported
Report period
December 31, 2022
Filed
February 14, 2023
Filing type
13F-HR
Position type
COM

Voting authority reported

Sole
14,371
Shared
0
None
2,706

“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.