Market Cap
$70.5M
SPRO
Spero Therapeutics, Inc.
$1.20 ▼ -4.76%
Prev close $1.26Market cap$70.5M
ConsensusStrong Sell
12-mo target$5.00 (+316.7%)
▼ Bearish
Analyst conviction 1/10
Insider Selling Cluster (2 insiders)High Impact Filing (7/10)7 New Institutional Positions Biotech & Drug Discovery
Snapshot
The big-picture read on SPRO right now — valuation, ownership and activity at a glance.
Cap Size
Micro Cap
Analyst Consensus
Sell (0%)
Inst. Holders
44 funds
Inst. Value
$20.3M
Inst. Activity
7 buys / 2 sells
Insider Activity
$0.00 buy / $456.6K sell
Insider Net $
-$456.6K
Social Sentiment
70° Bullish
SEC Reports
9
Press Releases
4
Price chart 30d -1.6%
Daily candles (open–high–low–close) with volume. Green = up day, red = down day.
No data for this timeframe.
Vol
Recent activity
The latest filings, insider trades, analyst actions, press and options flow — newest first.
Sep 11, 2026 SEC Aug 28, 2026 SEC Aug 28, 2026 SEC
The SEC declared effective Spero Therapeutics' S-3 shelf registration (File No. 333-298641) on September 10, 2026, enabl
EFFECT — Impact 7/10
Spero Therapeutics entered into a new at-the-market (ATM) equity offering agreement with Jefferies LLC for up to $100M i
8-K — Impact 7/10
Spero Therapeutics filed a universal shelf registration statement (S-3) to register up to $300M in securities, including
S-3 — Impact 7/10
Aug 12, 2026 earnings
Spero Therapeutics Announces Second Quarter 2026 Operating Results and Provides Business Update
CAMBRIDGE, Mass., Aug. 12, 2026 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a clini
Aug 3, 2026 Insider
Zack Debra was granted 324,675 shares
Chief Medical Officer
Aug 3, 2026 Insider
Jul 14, 2026 Press Zack Debra was granted 162,311 shares
Chief Medical Officer
Spero Therapeutics in-licensed global rights (ex-China) to SP001 (IBI355), a third-generation anti-CD40L antibody, from
Impact 7/10
Jun 30, 2026 Inst.
SUSQUEHANNA INTERNATIONAL GROUP, LLP — DOUBLED
759,290 shares ($1.7M)
Analyst ratings buy % +0.0%
How Wall Street rates the stock today, and the latest firm-by-firm actions.
0% rate it Buy or better · 6 analysts
Recent analyst actions
| Date | Firm | Action | Rating | Firm rating |
|---|---|---|---|---|
| Sep 14, 2026 | HC Wainwright & Co. | MAINTAIN | Buy | 43% |
Monthly consensus history
| Period | Str. Buy | Buy | Hold | Sell | Str. Sell | Buy % | Distribution |
|---|---|---|---|---|---|---|---|
| Sep 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Aug 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Jul 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Jun 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| May 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Apr 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Mar 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% | |
| Feb 1, 2026 | 0 | 0 | 3 | 1 | 2 | 0% |
Price targets
Where 2 covering analysts think SPRO trades over the next 12 months.
$5.00 +316.7% upside Strong Buy
Current$1.20 Low$4.00 Median$5.00 High$6.00 2 analysts
$4.00$6.00
Analyst rating None as of Oct 2, 2026
Social media sentiment mood +20.0%
Retail-investor mood aggregated across social media. 0° = very bearish, 100° = very bullish.
70°
Bullish
BearishNeutralBullish
Recent posts
SPRO Spero Therapeutics FDA approval and then drops? Cheaper buyout?
▲ 1 · 💬 1· ⚡ 0.5
SPRO just delayed?
▲ 1 · 💬 5· ⚡ 0.5
SPRO valuation disconnect?
▲ 1 · 💬 1· ⚡ 0.5
Spero Therapeutics $SPRO
▲ 1 · 💬 1· ⚡ 0.5
SPRO Pending FDA Approval June 18th Likely to go through because the trials were stopped early due to positive efficacy!
▲ 1 · 💬 0· ⚡ 0.5
Reports & filings
AI-scored summaries of recent SEC filings and press releases, with sentiment and impact.
9 SEC filing reports analyzed · 2 bullish, 3 bearish, 1 mixed, 3 neutral · avg impact 5.8/10.Plus 4 press releases.
BEARISHEFFECT7/10
The SEC declared effective Spero Therapeutics' S-3 shelf registration (File No. 333-298641) on Septe
Sep 11, 2026
BEARISH8-K7/10
Spero Therapeutics entered into a new at-the-market (ATM) equity offering agreement with Jefferies L
Aug 28, 2026
BEARISHS-37/10
Spero Therapeutics filed a universal shelf registration statement (S-3) to register up to $300M in s
Aug 28, 2026
NEUTRALPRESS-RELEASE4/10
Spero Therapeutics reported Q2 2026 financial results, highlighting a net loss of $11.0 million for
Aug 12, 2026
Upcoming & catalyst events
Scheduled dates plus disclosed catalysts — earnings, dividends, enforcement, FDA and clinical-trial events. Colored dot = impact.
Aug 12, 2026
earnings
Spero Therapeutics Announces Second Quarter 2026 Operating Results and Provides Business Update
CAMBRIDGE, Mass., Aug. 12, 2026 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a clinical-stage biopharmaceutical company focused on adv
Aug 12, 2026
earnings_calendar
SPRO Q2 2026 Earnings Scheduled — 2026-08-12
Jul 31, 2026
short_interest_report
Short Interest: SPRO down 28% to 1.5M shares
Settlement 2026-07-31 | Days to cover: 1.00 | ≈2.61% of shares outstanding (est.)
Jul 15, 2026
short_interest_report
Short Interest: SPRO down 26% to 2.1M shares
Settlement 2026-07-15 | Days to cover: 1.28 | ≈3.65% of shares outstanding (est.)
Jul 14, 2026
other
Spero Therapeutics Announces $105 Million Non-Recourse Non-Dilutive Financing Backed by a Portion of Utebzi Milestones & Royalties
CAMBRIDGE, Mass., July 14, 2026 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a clinical-stage biopharmaceutical company focused on adv
Earnings estimates
Forecast earnings per share and revenue by period — and whether estimates are rising.
| Period | EPS Est. | Range | Growth | 30d Rev | Up/Dn | Revenue | # |
|---|---|---|---|---|---|---|---|
| Current Q | $-0.14 | $-0.14–$-0.14 | -7.7% | — | 1↑ 0↓ | $0.0B | 1 |
| Next Q | $-0.14 | $-0.14–$-0.14 | — | — | 1↑ 0↓ | $0.0B | 1 |
| Current FY | $-0.58 | $-0.58–$-0.58 | -486.7% | -100.0% | — | $0.0B | 1 |
| Next FY | $-0.10 | $-0.88–$0.67 | 81.9% | -115.7% | 1↑ 0↓ | $0.0B | 2 |
Current-quarter EPS estimate — revision history
| When | EPS estimate | Change vs now |
|---|---|---|
| Current | $-0.140 | — |
| 7d ago | $0.000 | -0.140 |
| 30d ago | $0.000 | -0.140 |
| 60d ago | $0.000 | -0.140 |
| 90d ago | $0.000 | -0.140 |
Institutional ownership
Which big funds own SPRO (from quarterly 13F filings) and who is adding or trimming.
44 institutional holders with $20.3M total value (9,172,597 shares) as of 2026-Q2. Top holders: VANGUARD, RENAISSANCE, Alphabet. Net buying activity: 7 institutions added/increased vs 2 reduced.
Top holders — 2026-Q2
| Fund | Shares | Value | % Tracked | Last move |
|---|---|---|---|---|
| VANGUARD CAPITAL MANAGEMENT LLC | 2,036,226 | $4.5M | 22.2% | — |
| RENAISSANCE TECHNOLOGIES LLC | 947,904 | $2.1M | 10.3% | ADD +74.6% |
| Alphabet Inc. | 889,979 | $2.0M | 9.7% | — |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | 759,290 | $1.7M | 8.3% | DOUBLED +127.9% |
| BlackRock, Inc. | 594,404 | $1.3M | 6.5% | ADD +37.2% |
| GEODE CAPITAL MANAGEMENT, LLC | 566,329 | $1.3M | 6.2% | — |
| RAYMOND JAMES FINANCIAL INC | 521,705 | $1.2M | 5.7% | — |
| TWO SIGMA INVESTMENTS, LP | 382,814 | $846.0K | 4.2% | DOUBLED +654.2% |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 332,970 | $735.9K | 3.6% | — |
| VANGUARD FIDUCIARY TRUST CO | 287,648 | $635.7K | 3.1% | — |
Recent position changes
| Fund | Action | Prev | Current | Change | Value |
|---|---|---|---|---|---|
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | DOUBLED | 333,115 | 759,290 | +127.9% | $1.7M |
| BlackRock, Inc. | ADD | 433,202 | 594,404 | +37.2% | $1.3M |
| DIMENSIONAL FUND ADVISORS LP | DOUBLED | 29,768 | 274,820 | +823.2% | $607.6K |
| JANE STREET GROUP, LLC | ADD | 106,345 | 158,097 | +48.7% | $349.4K |
| UBS Group AG | DOUBLED | 3,009 | 139,680 | +4542.1% | $308.7K |
| Point72 Asset Management, L.P. | ADD | 59,668 | 104,377 | +74.9% | $230.7K |
| SIMPLEX TRADING, LLC | DOUBLED | 30,304 | 61,312 | +102.3% | $135.5K |
| CITIGROUP INC | TRIM | 19,135 | 9,625 | -49.7% | $21.3K |
| MORGAN STANLEY | NEAR_EXIT | 4,552 | 914 | -79.9% | $2.0K |
| Squarepoint Ops LLC | ADD | 119,434 | 194,301 | +62.7% | $454.7K |
Insider activity
Buying and selling by company executives and directors (SEC Form 4).
10 insiders, 28 transactions. Net -$456.6K — $0.00 bought, $456.6K sold.
| Date | Insider | Title | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 3, 2026 | Zack Debra | Chief Medical Officer | AWARD | 324,675 | — | — |
| Aug 3, 2026 | Zack Debra | Chief Medical Officer | AWARD | 162,311 | — | — |
| Jun 23, 2026 | Pottage John C Jr | Director | AWARD | 10,000 | — | — |
| Jun 23, 2026 | Jackson Scott Thomas | Director | AWARD | 10,000 | — | — |
| Jun 23, 2026 | Pottage John C Jr | Director | AWARD | 20,000 | — | — |
| Jun 23, 2026 | Jackson Scott Thomas | Director | AWARD | 20,000 | — | — |
| Jun 23, 2026 | THOMAS FRANK E | Director | AWARD | 10,000 | — | — |
| Jun 23, 2026 | THOMAS FRANK E | Director | AWARD | 20,000 | — | — |
| Jun 23, 2026 | VINK PATRICK V.J.J. | Director | AWARD | 10,000 | — | — |
| Jun 23, 2026 | VINK PATRICK V.J.J. | Director | AWARD | 20,000 | — | — |
Short interest & halts
FINRA semi-monthly short positions, Reg SHO threshold status, and recent trading halts for SPRO.
Shares short
976,488
Settlement Sep 15, 2026
Change vs prior
-19.3%
Semi-monthly cycle
Days to cover
3.1
At avg daily volume
Of shares outstanding
≈1.7%
Estimate — not % of float
All SPRO filing & press-release reports (13)
- EFFECT reportSep 11, 2026
- 8-K reportAug 28, 2026
- S-3 reportAug 28, 2026
- PRESS-RELEASE reportAug 12, 2026
- 8-K reportJul 14, 2026
- PRESS-RELEASE reportJul 14, 2026
- 8-K reportJun 26, 2026
- 8-K reportJun 23, 2026
- PRESS-RELEASE reportJun 17, 2026
- 8-K reportMay 13, 2026
- DEFA14A reportApr 27, 2026
- PRESS-RELEASE reportMar 26, 2026
- PRESS-RELEASE reportMar 18, 2026