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 32 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	GSK plc CIK 1131399 · View history	$11.12M 9,190,606 shares	2.24%	0(0.00%)Unchanged	SEC filing ↗ Nov 5, 2026	▾
02	Pfizer Inc CIK 78003 · View history	$2.91M 2,362,348 shares	1.77%	0(0.00%)Unchanged	SEC filing ↗ Nov 12, 2026	▾
03	MACKENZIE FINANCIAL CORP CIK 919859 · View history	$2.22M 1,831,254 shares	0.00%	+1.83MNew	SEC filing ↗ Nov 2, 2026	▾
04	RENAISSANCE TECHNOLOGIES LLC CIK 1037389 · View history	$1.71M 1,409,783 shares	0.00%	+461.88K(+48.70%)Added	SEC filing ↗ Nov 12, 2026	▾
05	RAYMOND JAMES FINANCIAL INC CIK 720005 · View history	$914.32K 755,633 shares	0.00%	+233.93K(+44.80%)Added	SEC filing ↗ Nov 12, 2026	▾
06	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$604.43K 499,271 shares	0.00%	-67.06K(-11.80%)Reduced	SEC filing ↗ Nov 6, 2026	▾
07	STATE STREET CORP CIK 93751 · View history	$304.01K 251,251 shares	0.00%	+36.50K(+17.00%)Added	SEC filing ↗ Nov 12, 2026	▾
08	Invesco Ltd. CIK 914208 · View history	$200.29K 165,530 shares	0.00%	+101.28K(+157.70%)Added	SEC filing ↗ Nov 12, 2026	▾
09	Employees Retirement System of Texas CIK 1398739 · View history	$151.00K 125,081 shares	0.00%	+125.08KNew	SEC filing ↗ Nov 10, 2026	▾
10	Squarepoint Ops LLC CIK 1642575 · View history	$114.32K 94,478 shares	0.00%	+94.48KNew	SEC filing ↗ Nov 9, 2026	▾
11	DIMENSIONAL FUND ADVISORS LP CIK 354204 · View history	$110.41K 91,287 shares	0.00%	-183.53K(-66.80%)Reduced	SEC filing ↗ Nov 4, 2026	▾
12	StoneX Group Inc. CIK 913760 · View history	$45.84K 38,241 shares	0.00%	+38.24KNew	SEC filing ↗ Nov 3, 2026	▾
13	SIMPLEX TRADING, LLC CIK 1488542 · View history	$44.56K 36,830 shares	0.00%	-24.48K(-39.90%)Reduced	SEC filing ↗ Nov 4, 2026	▾
14	PANAGORA ASSET MANAGEMENT INC CIK 883677 · View history	$39.64K 32,762 shares	0.00%	+32.76KNew	SEC filing ↗ Nov 12, 2026	▾
15	Capital Asset Advisory Services LLC CIK 1666024 · View history	$36.78K 32,548 shares	0.00%	0(0.00%)Unchanged	SEC filing ↗ Oct 30, 2026	▾
16	Three Seasons Wealth, LLC CIK 2044495 · View history	$36.30K 30,000 shares	0.00%	0(0.00%)Unchanged	SEC filing ↗ Nov 3, 2026	▾
17	OPPENHEIMER & CO INC CIK 822581 · View history	$32.37K 26,750 shares	0.00%	+3.90K(+17.10%)Added	SEC filing ↗ Oct 26, 2026	▾
18	RITHOLTZ WEALTH MANAGEMENT CIK 1698218 · View history	$25.05K 20,704 shares	0.00%	+20.70KNew	SEC filing ↗ Nov 5, 2026	▾
19	FNY Investment Advisers, LLC CIK 1742998 · View history	$25.00K 21,300 shares	0.01%	+13.00K(+156.60%)Added	SEC filing ↗ Oct 16, 2026	▾
20	JANE STREET GROUP, LLC CIK 1595888 · View history	$24.42K 20,185 shares	0.00%	-137.91K(-87.20%)Reduced	SEC filing ↗ Nov 12, 2026	▾

Showing 20 / 32 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

Cancelled or null records excluded

Disclosed shares

17,103,413

Not deduplicated across managers

Disclosed value

$20.74M

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. · Q3 2026

Explore all 32 reporting institutions.

This page includes 20 of 32 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.