Company · Ownership research

Spero Therapeutics, Inc. SPRO

CIK 0001701108 · CUSIP 84833T103

Insider tradingInitial holdingsInstitutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 84833T103 (SPRO), not CUSIP 84833T953 (SPRO), CUSIP 84833T903 (SPRO), and does not merge CUSIPs.

This page lists the top 20 of 51 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	Anson Funds Management LP CIK 1491072 · View history	$3.96M 3,839,886 shares	0.49%	+89.44K(+2.40%)Added	SEC filing ↗ Feb 14, 2025	▾
02	Pfizer Inc CIK 78003 · View history	$2.43M 2,362,348 shares	0.09%	—	SEC filing ↗ Feb 14, 2025	▾
03	VANGUARD GROUP INC CIK 102909 · View history	$1.82M 1,763,620 shares	0.00%	0(0.00%)Unchanged	SEC filing ↗ Feb 11, 2025	▾
04	RENAISSANCE TECHNOLOGIES LLC CIK 1037389 · View history	$1.14M 1,105,591 shares	0.00%	+130.94K(+13.40%)Added	SEC filing ↗ Feb 13, 2025	▾
05	ACADIAN ASSET MANAGEMENT LLC CIK 916542 · View history	$1.07M 1,039,922 shares	0.00%	-31.94K(-3.00%)Reduced	SEC filing ↗ Feb 11, 2025	▾
06	Alphabet Inc. CIK 1652044 · View history	$916.68K 889,979 shares	0.05%	0(0.00%)Unchanged	SEC filing ↗ Feb 7, 2025	▾
07	Murchinson Ltd. CIK 1838556 · View history	$900.13K 873,910 shares	0.40%	+873.91KNew	SEC filing ↗ Feb 14, 2025	▾
08	ADAR1 Capital Management, LLC CIK 1940272 · View history	$825.32K 801,277 shares	0.17%	+57.82K(+7.80%)Added	SEC filing ↗ Feb 13, 2025	▾
09	BlackRock, Inc. CIK 2012383 · View history	$499.91K 485,352 shares	0.00%	+532(+0.10%)Added	SEC filing ↗ Feb 7, 2025	▾
10	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$495.70K 481,128 shares	0.00%	-59(0.00%)Reduced	SEC filing ↗ Feb 12, 2025	▾
11	MONIMUS CAPITAL MANAGEMENT, LP CIK 1848831 · View history	$320.24K 310,908 shares	0.30%	—	SEC filing ↗ Feb 10, 2025	▾
12	Atlas Venture Life Science Advisors, LLC CIK 1917529 · View history	$314.41K 305,255 shares	0.04%	-97.63K(-24.20%)Reduced	SEC filing ↗ Feb 6, 2025	▾
13	MACKENZIE FINANCIAL CORP CIK 919859 · Amended · View history	$193.19K 187,559 shares	0.00%	+155.66K(+487.90%)Added	SEC filing ↗ May 2, 2025	▾
14	BRIDGEWAY CAPITAL MANAGEMENT, LLC CIK 1107261 · View history	$190.34K 184,800 shares	0.00%	0(0.00%)Unchanged	SEC filing ↗ Feb 14, 2025	▾
15	CITADEL ADVISORS LLC CIK 1423053 · View history	$178.06K 172,872 shares	0.00%	+91.45K(+112.30%)Added	SEC filing ↗ Feb 14, 2025	▾
16	STATE STREET CORP CIK 93751 · View history	$153.38K 148,911 shares	0.00%	+18.40K(+14.10%)Added	SEC filing ↗ Feb 14, 2025	▾
17	DAFNA Capital Management LLC CIK 1389933 · View history	$128.75K 125,000 shares	0.03%	0(0.00%)Unchanged	SEC filing ↗ Feb 14, 2025	▾
18	NORTHERN TRUST CORP CIK 73124 · View history	$89.04K 86,447 shares	0.00%	-25.05K(-22.50%)Reduced	SEC filing ↗ Feb 14, 2025	▾
19	JPMORGAN CHASE & CO CIK 19617 · View history	$63.47K 61,624 shares	0.00%	+61.39K(+26,011.90%)Added	SEC filing ↗ Feb 12, 2025	▾
20	Squarepoint Ops LLC CIK 1642575 · View history	$56.70K 55,051 shares	0.00%	+55.05KNew	SEC filing ↗ Feb 14, 2025	▾

Showing 20 / 51 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

Cancelled or null records excluded

Disclosed shares

15,679,985

Not deduplicated across managers

Disclosed value

$16.15M

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

Spero Therapeutics, Inc. · Q4 2024

Explore all 51 reporting institutions.

This page includes 20 of 51 reporting institutions. Log in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.