Spero Therapeutics, Inc. (SPRO)
Nasdaq: SPRO · Pharmaceutical Preparations · Cambridge, MA · filing with the SEC since 2017
Who owns Spero Therapeutics, Inc.
As filed with the SECHolders of 5% or more
1
GSK plc holds 16.4% of Common Stock, Par Value $0.001, as its SCHEDULE 13D/A filed Mar 28, 2025 says.
Directors and officers
12
report now, of 25 people on the record since 2017. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 1 named at left.
Holders of 5% or moreshare of the class, as filed
GSK plc
SCHEDULE 13D/A · filed Mar 28, 2025 · Common Stock, Par Value $0.001
Anson Funds Management LP
SCHEDULE 13G/A · filed Aug 14, 2025 · Common Stock, par value $0.001 per share · reported falling below 5%
What SPRO reports owning in othersstakes of 5% or more, and other ties
Spero Therapeutics, Inc. reports no stake in another company in the record.
Insider tradesForm 4
9sales
0purchases
0sales on a scheduled plan
2people selling
$500,000sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Nov 10, 2025 to Nov 10, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2026 runs to Nov 10, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window2 of 35 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Rajavelu Esther | See Remarks | 5 | $400,000 | 0 | 0 | $0 |
| Keutzer Timothy | Chief Operating Officer | 4 | $100,000 | 0 | 0 | $0 |