GROUP ONE TRADING LLC

Position in SPRO — Spero Therapeutics, Inc.

CIK 932540 CHICAGO, IL

Position in SPRO

as of Jun 30, 2026 · filed Aug 14, 2026 Compact

Position Value

$24,020

-$7,712 QoQ

Shares Held

10,869

-35.6% QoQ

Ownership

0.019%

of shares outstanding

% of Portfolio

0.00%

of 13F equity value

Holder Rank

#44

of 59 holders

Holding Since

Jun 2020

12 quarters on record

Voting authority Sole 100% Shared 0% None 0%

Healthcare · as of Jun 30, 2026

GROUP ONE TRADING LLC holds $113,693,049 across 200 Biotechnology names. SPRO ranks #106 (0.0% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	MRNA	Moderna, Inc.	203,915	$14,280,167
2	VKTX	Viking Therapeutics, Inc.	261,443	$10,198,891
3	CAPR	Capricor Therapeutics, Inc.	272,609	$6,564,424
4	ABSI	Absci Corp	524,747	$6,081,817
5	AGIO	Agios Pharmaceuticals, Inc.	151,994	$5,640,497
6	NKTR	Nektar Therapeutics	70,371	$4,912,599
7	CRSP	CRISPR Therapeutics AG	85,040	$4,638,081
8	ABVX	Abivax S.A.	29,767	$3,966,750

12 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$24,020	10,869	-35.6%	Shares	Sole	2026-08-14
2025-09-30	$31,732	16,879	+104.9%	Shares	Sole	2025-11-12
2025-06-30	$23,893	8,239	+79.5%	Shares	Sole	2025-08-14
2023-12-31	$6,747	4,590	-86.6%	Shares	Sole	2024-02-14
2023-09-30	$41,369	34,190	-62.8%	Shares	Sole	2023-11-09
2023-06-30	$133,356	91,970	+5.6%	Shares	Sole	2023-08-09
2023-03-31	$126,300	87,104	+1417.2%	Shares	Sole	2023-05-12
2022-12-31	$9,931	5,741	-89.6%	Shares	Sole	2023-02-09
2022-09-30	$110,200	55,100	+127.3%	Shares	Sole	2022-11-09
2022-06-30	$17,964	24,244	+433.1%	Shares	Sole	2022-08-11
2020-09-30	$50,755	4,548	+49.2%	Shares	Sole	2020-11-12
2020-06-30	$41,239	3,048	—	Shares	Sole	2020-08-13
No filing history on record for this holder in this stock.