Company · Ownership research

Spero Therapeutics, Inc. SPRO

CIK 0001701108 · CUSIP 84833T103

Insider trading Initial holdings Institutional 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 55 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	$6.45M 3,750,450 shares	0.46%	-547.25K(-12.70%)Reduced	SEC filing ↗ May 14, 2024	▾
02	VANGUARD GROUP INC CIK 102909 · View history	$2.84M 1,653,432 shares	0.00%	+9.68K(+0.60%)Added	SEC filing ↗ May 10, 2024	▾
03	ADAR1 Capital Management, LLC CIK 1940272 · View history	$1.59M 926,929 shares	0.44%	-140.78K(-13.20%)Reduced	SEC filing ↗ May 15, 2024	▾
04	Alphabet Inc. CIK 1652044 · View history	$1.53M 889,979 shares	0.06%	0(0.00%)Unchanged	SEC filing ↗ May 3, 2024	▾
05	Murchinson Ltd. CIK 1838556 · Amended · View history	$1.50M 873,910 shares	0.17%	+11.21K(+1.30%)Added	SEC filing ↗ May 16, 2024	▾
06	RENAISSANCE TECHNOLOGIES LLC CIK 1037389 · View history	$1.47M 854,460 shares	0.00%	+307.00K(+56.10%)Added	SEC filing ↗ May 13, 2024	▾
07	ACADIAN ASSET MANAGEMENT LLC CIK 916542 · View history	$1.31M 762,598 shares	0.00%	+418.74K(+121.80%)Added	SEC filing ↗ May 10, 2024	▾
08	Atlas Venture Life Science Advisors, LLC CIK 1917529 · View history	$1.05M 607,613 shares	0.10%	-405.82K(-40.00%)Reduced	SEC filing ↗ May 6, 2024	▾
09	BlackRock Inc. CIK 1364742 · View history	$820.26K 476,896 shares	0.00%	-3.70K(-0.80%)Reduced	SEC filing ↗ May 10, 2024	▾
10	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$807.63K 469,441 shares	0.00%	+56.73K(+13.70%)Added	SEC filing ↗ May 13, 2024	▾
11	NOVO HOLDINGS A/S CIK 1388325 · View history	$806.51K 468,902 shares	0.06%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2024	▾
12	AWM Investment Company, Inc. CIK 1535264 · View history	$573.45K 333,400 shares	0.08%	0(0.00%)Unchanged	SEC filing ↗ May 16, 2024	▾
13	Shay Capital LLC CIK 1723643 · View history	$527.98K 306,967 shares	0.15%	+306.97KNew	SEC filing ↗ May 15, 2024	▾
14	Man Group plc CIK 1637460 · View history	$368.13K 214,026 shares	0.00%	+214.03KNew	SEC filing ↗ May 15, 2024	▾
15	BRIDGEWAY CAPITAL MANAGEMENT, LLC CIK 1107261 · View history	$317.86K 184,800 shares	0.01%	+50.00K(+37.10%)Added	SEC filing ↗ May 15, 2024	▾
16	MILLENNIUM MANAGEMENT LLC CIK 1273087 · View history	$254.34K 147,872 shares	0.00%	-985(-0.70%)Reduced	SEC filing ↗ May 15, 2024	▾
17	STATE STREET CORP CIK 93751 · View history	$224.48K 130,511 shares	0.00%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2024	▾
18	DAFNA Capital Management LLC CIK 1389933 · View history	$215.00K 125,000 shares	0.05%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2024	▾
19	NORTHERN TRUST CORP CIK 73124 · View history	$197.04K 114,559 shares	0.00%	+25.68K(+28.90%)Added	SEC filing ↗ May 14, 2024	▾
20	BANK OF MONTREAL /CAN/ CIK 927971 · View history	$139.92K 79,500 shares	0.00%	+79.50KNew	SEC filing ↗ May 13, 2024	▾

Showing 20 / 55 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

Cancelled or null records excluded

Disclosed shares

13,757,012

Not deduplicated across managers

Disclosed value

$23.67M

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. · Q1 2024

Explore all 55 reporting institutions.

This page includes 20 of 55 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.