Spero Therapeutics SPRO Institutional Ownership

NASDAQ SPRO

$1.12 -0.05 (-4.27%)

At close: Sep 10, 2026 · 4:00 PM EDT

Institutions by Trading Activity

62 Institutions

Increased 39 62.9%

Unchanged 17 27.4%

Reduced 6 9.7%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

37.06%

▲+1.02 pp QoQ

Shares Held by Institutions

21.48Mn

of 57.97Mn outstanding

▲+11.06% QoQ

Shares Outstanding

57.97Mn

36.49Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▲+12 vs prior quarter

Net Shares Added (QoQ)

+2.14Mn

accumulated since last quarter

Value of Holdings

$25.99Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Quarter ending 30 Jun, 2026

Spero Therapeutics, Inc. (NASDAQ:SPRO) showed up in the 13F filings of 62 institutional investors as of June 2026.

They owned 37.1% of outstanding stock in June 2026, up from 36.0% the prior quarter.
They increased total shares held in Spero Therapeutics by 11.06% from the prior quarter, while the number of investors in SPRO increased 44.19% year over year.
Activity in SPRO broke down as 39 buyers, 6 sellers, and 17 unchanged among 62 total holders.
The aggregate institutional position in Spero Therapeutics amounted to 21.48Mn shares as of June 2026, up by 2.14Mn shares quarter on quarter, and up 10.51Mn shares year over year.
As of June 30, 2026, GSK plc held the largest stake in Spero Therapeutics with 9.19Mn shares, accounting for 15.85% of total shares outstanding.
The largest buyers of Spero Therapeutics for the quarter ending June 2026 were Raymond James Financial Inc (521.71K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (426.18K), ARROWSTREET CAPITAL, LIMITED PARTNERSHIP (332.97K), Goldman Sachs Group Inc (256.98K), DIMENSIONAL FUND ADVISORS LP (245.05K).
The largest sellers of Spero Therapeutics for the quarter ending June 2026 were TWO SIGMA INVESTMENTS, LP (502.82K), RENAISSANCE TECHNOLOGIES LLC (241.33K), Ionic Capital Management LLC (93.24K), Northern Trust Corp (12.71K), Citigroup Inc (9.51K).
Per Business Quant, the top 10 investors in SPRO for the quarter ending June 2026 include GSK plc (9.19Mn), Pfizer Inc (2.36Mn), VANGUARD CAPITAL MANAGEMENT LLC (2.04Mn), RENAISSANCE TECHNOLOGIES LLC (947.9K), Alphabet Inc. (889.98K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (759.29K), BlackRock, Inc. (594.4K), GEODE CAPITAL MANAGEMENT, LLC (566.33K), Raymond James Financial Inc (521.71K), TWO SIGMA INVESTMENTS, LP (382.81K).

Form 13F Holdings

62 Institutional Holders

Report period 30 Jun, 2026

Total shares held 21.48Mn

Of outstanding 37.06%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	GSK plc	0001131399	9,190,606	15.85%	0	0.00%	$20.31Mn
2	Pfizer Inc	0000078003	2,362,348	4.08%	0	0.00%	$5.34Mn
3	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	2,036,226	3.51%	▲236,346	+13.13%	$4.50Mn
4	RENAISSANCE TECHNOLOGIES LLC	0001037389	947,904	1.64%	▼241,331	-20.29%	$2.09Mn
5	Alphabet Inc.	0001652044	889,979	1.54%	0	0.00%	$1.97Mn
6	SUSQUEHANNA INTERNATIONAL GROUP, LLP	0001446194	759,290	1.31%	▲426,175	+127.94%	$1.68Mn
7	BlackRock, Inc.	0002012383	594,404	1.03%	▲161,202	+37.21%	$1.31Mn
8	GEODE CAPITAL MANAGEMENT, LLC	0001214717	566,329	0.98%	▲46,407	+8.93%	$1.25Mn
9	Raymond James Financial Inc	0000720005	521,705	0.90%	▲521,705	0.00%	$1.15Mn
10	TWO SIGMA INVESTMENTS, LP	0001179392	382,814	0.66%	▼502,817	-56.78%	$846.02K
11	ARROWSTREET CAPITAL, LIMITED PARTNERSHIP	0001164508	332,970	0.57%	▲332,970	0.00%	$735.86K
12	VANGUARD FIDUCIARY TRUST CO	0000933478	287,648	0.50%	▲23,533	+8.91%	$635.70K
13	GSA CAPITAL PARTNERS LLP	0001362033	285,906	0.49%	▲7,602	+2.73%	$632
14	DIMENSIONAL FUND ADVISORS LP	0000354204	274,820	0.47%	▲245,052	+823.21%	$607.62K
15	Goldman Sachs Group Inc	0000886982	256,985	0.44%	▲256,985	0.00%	$567.94K
16	State Street Corp	0000093751	214,751	0.37%	0	0.00%	$474.60K
17	JANE STREET GROUP, LLC	0001595888	158,097	0.27%	▲51,752	+48.66%	$349.39K
18	UBS Group AG	0001610520	139,680	0.24%	▲136,671	+4,542.07%	$308.69K
19	BRIDGEWAY CAPITAL MANAGEMENT, LLC	0001107261	114,800	0.20%	0	0.00%	$253.71K
20	Northern Trust Corp	0000073124	108,274	0.19%	▼12,710	-10.51%	$239.29K

Showing 1 to 20 of 62 holders