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Spero Therapeutics, Inc. Stock: price and insider trades · United States
No insider purchase over the last 90 days. The latest was filed 28 Apr 2022.
Spero Therapeutics, Inc.: what insiders have been doing
Spero Therapeutics, Inc. belongs to the Healthcare & Pharma sector. Filings by its managers are published through SEC (Form 4). Between 18 October 2025 and 18 October 2026, 5 insiders published 8 filings.
Only sales appear on the open market, 3 sales in all totalling €194k, filed by 2 insiders. Biggest ticket of the year: €83k, sold by Rajavelu Esther and made public on 12 November 2025.
The median gap between a trade and its publication by SEC (Form 4) is 3 days. The legal deadline for a Form 4 is two business days after the transaction. A sale on its own says little: insiders also sell to pay tax, fund a purchase or diversify.
With 8 filings in twelve months, the company is quieter than the median of 19 filings across the 5,816 companies we follow on the same exchange. Our records for Spero Therapeutics, Inc. go back to 2021, with 17 purchases and 20 sales on the open market in total. For the fiscal year to 31 December 2025, the annual 10-K puts revenue at 66.8 m USD and net income at 8.6 m USD.
For comparison within the same sector, see the insider buying recorded at Cooper Companies, Inc. and Anixa Biosciences Inc. Source: insider filings from SEC (Form 4). Past trades are no guide to future returns.
Insider Decl.
104
Thresholds
n/a
Buy Volume
€13M
17 ops. · all time
Sell Volume
€4M
20 ops. · all time
Who traded when
BuySaleEsther Rajavelu3 sales
Ankit Mahadevia2 sales
Timothy Keutzer2 sales
Since the insiders bought
- -61.9%Entry US$4.86 · Close at T+365 US$1.85
Entry is the close on the day after publication, the first price a reader could act on. Prices in the listing currency. Past moves are not a forecast.
This score ranks the purchase within its own market. A position size is suggested only on the venues of the backtested strategy universe; elsewhere, signals stay on watch. Not investment advice.
Fundamental score
Ranked 4,227 of 24,148 companies
68.3
score / 100
Value55
Quality82
FCF yld-20%
Earn yld13%
EV/EBITDA9.4x
ROE19%
Gross mgn·
Net mgn14%
Debt/EBITDA0.4x
Pillars2/3
Transparent value + quality ranking, distinct from the insider signal.
Financial data
as of FY 2025FY ended December 2025 · cache
US$1.15
Analyst consensus
2 analysts2.00/5
US$4.00Target US$5.00(+335%)US$6.00
Income statement
RevenueUS$59.6M
EBITDAUS$7.2M12% margin
Net incomeUS$8.6M15.7% margin
Valuation
PER (trailing)8.2x
P/Book1.5x
Beta1.50
Balance sheet & cash
Market capUS$67M
Total debtUS$2.9M
Free Cash Flow-US$12.6M
Debt / Equity5%
Profitability & ownership
ROE19.2%
ROA7.2%
% insiders22.7%
% institutions18.3%
Last declaration on 6 August 2026
Declarations104 total
162,311 shares0Common StockSEC:0001807743-26-000007:0
10,000 sharesCommon StockSEC:0001193125-26-283202:0
10,000 sharesCommon StockSEC:0001193125-26-283245:0
37,101 shares@ US$2.3640.1% of flowCommon StockSEC:0001193125-26-043336:0
18,652 shares@ US$2.3682.9% of flowCommon StockSEC:0001193125-26-043315:0
68,000 shares0Common StockSEC:0001193125-26-038441:0
249,000 shares0Common StockSEC:0001193125-26-038184:0
40,270 shares@ US$2.3744.6% of flowCommon StockSEC:0001193125-25-278370:0
6,572 shares@ US$1.976.1% of flowCommon StockSEC:0000950170-25-112661:0
1,695 shares@ US$1.976.3% of flowCommon StockSEC:0000950170-25-112659:0
20,000 shares0Common StockSEC:0000950170-25-087021:0
20,000 shares0Common StockSEC:0000950170-25-087020:0
20,000 shares0Common StockSEC:0000950170-25-087017:0
20,000 shares0Common StockSEC:0000950170-25-087015:0
20,000 shares0Common StockSEC:0000950170-25-087013:0
20,000 shares0Common StockSEC:0000950170-25-087010:0
20,000 shares0Common StockSEC:0000950170-25-087009:0
20,000 shares0Common StockSEC:0000950170-25-087008:0
185,000 shares0Common StockSEC:0000950170-25-064821:0
13,959 shares@ US$0.785.8% of flowCommon StockSEC:0000950170-25-014849:0
751,407 shares0Common StockSEC:0000950170-25-014850:0
266,139 shares0Common StockSEC:0000950170-25-014859:0
266,139 shares0Common StockSEC:0000950170-25-014866:0
23,351 shares@ US$1.3115.4% of flowCommon StockSEC:0000950170-24-125339:0
2,757 shares@ US$1.3511.5% of flowCommon StockSEC:0000950170-24-101993:0
25 of 104 declarations
About Spero Therapeutics, Inc.
Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company listed on the Nasdaq (United States) under the ticker SPRO. Headquartered in Cambridge, Massachusetts, United States, the company was founded in 2013 and has built its strategy around unmet medical needs in multidrug-resistant (MDR) bacterial infections and selected rare diseases. From an equity research perspective, Spero is best viewed as a niche, catalyst-driven biotech rather than a commercial-stage pharmaceutical company: valuation is primarily tied to clinical readouts, regulatory milestones, licensing economics, and balance-sheet durability. ([sperotherapeutics.com](https://www.sperotherapeutics.com/about-us?utm_source=openai))
The lead asset is tebipenem HBr, an investigational oral carbapenem being developed for complicated urinary tract infection (cUTI), including pyelonephritis. Spero states that it granted GSK an exclusive license to commercialize tebipenem HBr in all territories except certain Asian markets, which means the program is strategically important even though Spero is not the primary commercial operator. The pipeline also includes SPR720, an oral candidate for nontuberculous mycobacterial pulmonary disease (NTM-PD), but that development program has been suspended after a phase 2a analysis failed to support the target profile. SPR206, another anti-infective asset aimed at MDR Gram-negative infections, remains part of the broader scientific franchise but is not the company’s core near-term value driver. ([sperotherapeutics.com](https://www.sperotherapeutics.com/pipeline?utm_source=openai))
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In competitive terms, Spero occupies a specialized position in anti-infectives, focused on therapeutic areas where oral treatment options remain limited and intravenous care is still the standard of care. The strategic appeal of tebipenem HBr is that it could become the first oral carbapenem available in the United States if approved, potentially changing the treatment pathway for cUTI patients by enabling earlier discharge or avoiding hospitalization altogether. Spero does not compete on scale against large-cap pharma; instead, it competes on differentiation, clinical proof-of-concept, and regulatory execution. ([sperotherapeutics.com](https://www.sperotherapeutics.com/pipeline?utm_source=openai))
Recent developments have centered on tebipenem HBr. In May 2025, Spero and GSK announced that the pivotal phase 3 PIVOT-PO trial met its primary endpoint and would stop early for efficacy. GSK then submitted an NDA resubmission to the FDA in December 2025, and Spero’s 2025 annual report, published in 2026, stated that the FDA accepted that resubmission. For investors, SPRO is therefore a high-beta healthcare name on Nasdaq in the United States, with the investment case hinging mainly on the regulatory path for tebipenem HBr, partnership economics with GSK, and the company’s ability to preserve financial flexibility while it evaluates its next pipeline steps. ([gsk.com](https://www.gsk.com/en-gb/media/press-releases/pivot-po-phase-iii-study-for-tebipenem-hbr-stopped-early-for-efficacy-following-review-by-independent-data-monitoring-committee/?utm_source=openai))
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