Spero Therapeutics (SPRO) Stock Analysis & Price (Updated Oct 16, 2026, 4:00 PM ET)
Updated Oct 16, 2026, 4:00 PM ET
- Closed at $1.10, -2.65% vs the prior close of $1.13.
- Volume 361.23K shares, 0.6x its 50-day average (light).
- No new SEC filings since the prior session.
- No new insider buys or sales reported since the prior session.
SPRO dips 2.7% to $1.10, a 52-week low. Closed at $1.10, -2.65% vs the prior close of $1.13. Day range $1.09–$1.17, opened at $1.14.
SPRO daily analysis — what happened
A plain-English, data-only note written after every US trading day. Newest first; older days stay archived below.
Oct 16, 2026 — SPRO dips 2.7% to $1.10, a 52-week low
- Closed at $1.10, -2.65% vs the prior close of $1.13. Day range $1.09–$1.17, opened at $1.14.
- Volume was 361.23K shares, 0.6x its 50-day average of 636.53K — lighter than usual.
- Price is -7.8% vs its 50-day average ($1.19) and -46.4% vs its 200-day average ($2.05).
- 52-week range $1.08–$3.08; today's close sits at 1% of that range, 64.3% below the 52-week high.
Oct 15, 2026 — SPRO rises 0.9% to $1.13
- Closed at $1.13, +0.89% vs the prior close of $1.12. Day range $1.11–$1.14, opened at $1.12.
- Volume was 233.80K shares, 0.4x its 50-day average of 643.35K — lighter than usual.
- Price is -5.5% vs its 50-day average ($1.20) and -45.0% vs its 200-day average ($2.06).
- 52-week range $1.08–$3.08; today's close sits at 2% of that range, 63.3% below the 52-week high.
Oct 14, 2026 — SPRO dips 2.6% to $1.12, 3 down days in a row
- Closed at $1.12, -2.61% vs the prior close of $1.15. Day range $1.11–$1.17, opened at $1.15.
- Volume was 696.50K shares, 1.1x its 50-day average of 644.46K.
- Price is -6.6% vs its 50-day average ($1.20) and -45.7% vs its 200-day average ($2.06).
- 52-week range $1.08–$3.08; today's close sits at 2% of that range, 63.6% below the 52-week high.
- That makes 3 straight losses.
Oct 13, 2026 — SPRO dips 2.5% to $1.15
- Closed at $1.15, -2.54% vs the prior close of $1.18. Day range $1.15–$1.20, opened at $1.19.
- Volume was 272.50K shares, 0.4x its 50-day average of 666.47K — lighter than usual.
- Price is -4.3% vs its 50-day average ($1.20) and -44.4% vs its 200-day average ($2.07).
- 52-week range $1.08–$3.08; today's close sits at 3% of that range, 62.7% below the 52-week high.
Oct 12, 2026 — SPRO dips 1.7% to $1.18
- Closed at $1.18, -1.67% vs the prior close of $1.20. Day range $1.16–$1.22, opened at $1.20.
- Volume was 414.10K shares, 0.6x its 50-day average of 674.68K.
- Price is -1.8% vs its 50-day average ($1.20) and -43.1% vs its 200-day average ($2.07).
- 52-week range $1.08–$3.08; today's close sits at 5% of that range, 61.7% below the 52-week high.
Oct 9, 2026 — SPRO jumps 5.3% to $1.20
- Closed at $1.20, +5.26% vs the prior close of $1.14. Day range $1.13–$1.21, opened at $1.14.
- Volume was 438.80K shares, 0.6x its 50-day average of 675.63K.
- Price is -0.1% vs its 50-day average ($1.20) and -42.3% vs its 200-day average ($2.08).
- 52-week range $1.08–$3.08; today's close sits at 6% of that range, 61.0% below the 52-week high.
Oct 8, 2026 — SPRO dips 2.6% to $1.14
- Closed at $1.14, -2.56% vs the prior close of $1.17. Day range $1.13–$1.22, opened at $1.20.
- Volume was 718.90K shares, 1.1x its 50-day average of 682.37K.
- Price is -5.1% vs its 50-day average ($1.20) and -45.3% vs its 200-day average ($2.09).
- 52-week range $1.08–$3.08; today's close sits at 3% of that range, 63.0% below the 52-week high.
Oct 7, 2026 — SPRO dips 1.7% to $1.17
- Closed at $1.17, -1.68% vs the prior close of $1.19. Day range $1.16–$1.19, opened at $1.19.
- Volume was 233.60K shares, 0.3x its 50-day average of 709.74K — lighter than usual.
- Price is -2.7% vs its 50-day average ($1.20) and -44.1% vs its 200-day average ($2.09).
- 52-week range $1.08–$3.08; today's close sits at 4% of that range, 62.0% below the 52-week high.
Oct 6, 2026 — SPRO rises 2.6% to $1.19
- Closed at $1.19, +2.59% vs the prior close of $1.16. Day range $1.18–$1.24, opened at $1.21.
- Volume was 347.00K shares, 0.5x its 50-day average of 729.73K — lighter than usual.
- Price is -1.0% vs its 50-day average ($1.20) and -43.3% vs its 200-day average ($2.10).
- 52-week range $1.08–$3.08; today's close sits at 6% of that range, 61.4% below the 52-week high.
Oct 5, 2026 — SPRO dips 2.5% to $1.16
- Closed at $1.16, -2.52% vs the prior close of $1.19. Day range $1.15–$1.20, opened at $1.17.
- Volume was 935.70K shares, 1.0x its 50-day average of 946.37K.
- Price is -3.5% vs its 50-day average ($1.20) and -44.8% vs its 200-day average ($2.10).
- 52-week range $1.08–$3.08; today's close sits at 4% of that range, 62.3% below the 52-week high.
Oct 2, 2026 — SPRO slides 5.6% to $1.19
- Closed at $1.19, -5.56% vs the prior close of $1.26. Day range $1.17–$1.27, opened at $1.26.
- Volume was 906.90K shares, 0.9x its 50-day average of 1.00M.
- Price is -1.1% vs its 50-day average ($1.20) and -43.6% vs its 200-day average ($2.11).
- 52-week range $1.08–$3.08; today's close sits at 6% of that range, 61.4% below the 52-week high.
SPRO latest news & SEC filings
Every SEC filing by or about SPRO in the last 120 days, explained in plain English. Updated daily, with a same-day refresh for new filings.
Sep 10, 2026 · Form EFFECT — EFFECT filing
EFFECT filing
Aug 28, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 1.01 — Signed a material agreement.
- Item 8.01 — Reported other events the company considers important.
Aug 28, 2026 · Form S-3 — Shelf registration (S-3)
Shelf registration (S-3) — lets the company sell securities over time
An offering document: new shares or debt may be sold, which can increase the share count (dilution) or debt load. Size and terms are in the prospectus.
Aug 12, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 2.02 — Reported results of operations (earnings release).
This is a results-day filing: the earnings press release is attached as an exhibit.
Aug 12, 2026 · Form 10-Q — Quarterly report
Quarterly report (unaudited financial statements for the quarter)
Quarter ended Jun 30, 2026:
- Revenue: $0 (prior year $0)
- Net income: -$9.55M (prior year -$1.70M) (loss widened vs Jun 30, 2025)
- Diluted EPS: -$0.16 (prior year -$0.03) (loss widened vs Jun 30, 2025)
Aug 6, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
Insider holdings update with no common-stock transactions in the table (often options or derivative awards only).
Aug 6, 2026 · Form 3 — New insider holdings
Initial insider ownership statement (Form 3) — a new director, officer or 10% owner disclosed their holdings
Jul 14, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 1.01 — Signed a material agreement.
- Item 2.03 — Took on a new material debt or financial obligation.
- Item 7.01 — Released information under Regulation FD (e.g. a presentation or press release).
- Item 8.01 — Reported other events the company considers important.
Jun 25, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
Insider holdings update with no common-stock transactions in the table (often options or derivative awards only).
Jun 25, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
Insider holdings update with no common-stock transactions in the table (often options or derivative awards only).
Jun 25, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
Insider holdings update with no common-stock transactions in the table (often options or derivative awards only).
Jun 25, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
Insider holdings update with no common-stock transactions in the table (often options or derivative awards only).
Jun 25, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 5.02 — Change in directors or officers (appointment, departure or pay).
- Item 5.03 — Amended its charter or bylaws / changed fiscal year.
- Item 5.07 — Reported shareholder vote results.
Jun 23, 2026 · Form S-8 — Employee share plan registration
Registration of shares for employee stock plans (S-8)
Jun 22, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 7.01 — Released information under Regulation FD (e.g. a presentation or press release).
- Item 8.01 — Reported other events the company considers important.
Things to know before you trade SPRO
- Last results release: Aug 12, 2026 (8-K Item 2.02). Previous ones: May 13, 2026, Mar 26, 2026, Nov 13, 2025. Based on that rhythm, the next report is likely around Nov 11, 2026 — an estimate, not a confirmed date.
- How much it moves: over the last 20 sessions the average daily move was 3.48% (largest 19.3%). That is a volatile stock.
- Liquidity: about 919.07K shares (≈$1.01M) trade per day on average. Thin volume can mean wider bid/ask spreads.
- 52-week position: $1.10 vs a range of $1.08–$3.08 (1% of the range).
- Dividends: no cash dividends in the last 2 years.
- Splits: none in the last 2 years.
- Insider trades (Form 4, last 12 months, recent 25 shown): 0 open-market buys, 25 sales; latest: Esther Rajavelu sold 25,240 shares on May 4, 2026.
- Latest filings: 8-K Aug 28, 2026; 8-K Aug 12, 2026; 10-Q Aug 12, 2026.
- Share count: 58.23M shares outstanding (Aug 7, 2026), +3.5% vs a year earlier.
- Listing: Nasdaq · industry: Pharmaceutical Preparations.
SPRO market data (last 20 sessions)
| Date | Open | High | Low | Close | Volume |
|---|---|---|---|---|---|
| Oct 16, 2026 | 1.14 | 1.17 | 1.09 | 1.10 | 361.23K |
| Oct 15, 2026 | 1.12 | 1.14 | 1.11 | 1.13 | 233.80K |
| Oct 14, 2026 | 1.15 | 1.17 | 1.11 | 1.12 | 696.50K |
| Oct 13, 2026 | 1.19 | 1.20 | 1.15 | 1.15 | 272.50K |
| Oct 12, 2026 | 1.20 | 1.22 | 1.16 | 1.18 | 414.10K |
| Oct 9, 2026 | 1.14 | 1.21 | 1.13 | 1.20 | 438.80K |
| Oct 8, 2026 | 1.20 | 1.22 | 1.13 | 1.14 | 718.90K |
| Oct 7, 2026 | 1.19 | 1.19 | 1.16 | 1.17 | 233.60K |
| Oct 6, 2026 | 1.21 | 1.24 | 1.18 | 1.19 | 347.00K |
| Oct 5, 2026 | 1.17 | 1.20 | 1.15 | 1.16 | 935.70K |
| Oct 2, 2026 | 1.26 | 1.27 | 1.17 | 1.19 | 906.90K |
| Oct 1, 2026 | 1.22 | 1.31 | 1.20 | 1.26 | 1.04M |
| Sep 30, 2026 | 1.21 | 1.29 | 1.20 | 1.21 | 557.90K |
| Sep 29, 2026 | 1.20 | 1.22 | 1.17 | 1.20 | 334.90K |
| Sep 28, 2026 | 1.22 | 1.22 | 1.17 | 1.19 | 393.10K |
| Sep 25, 2026 | 1.27 | 1.29 | 1.21 | 1.23 | 541.80K |
| Sep 24, 2026 | 1.25 | 1.29 | 1.24 | 1.25 | 473.90K |
| Sep 23, 2026 | 1.36 | 1.40 | 1.24 | 1.26 | 1.40M |
| Sep 22, 2026 | 1.30 | 1.44 | 1.28 | 1.36 | 7.76M |
| Sep 21, 2026 | 1.14 | 1.15 | 1.12 | 1.14 | 319.10K |
About Spero Therapeutics
Spero Therapeutics (SPRO) is listed on the Nasdaq and classified by the SEC under “Pharmaceutical Preparations”. Its business address is in CAMBRIDGE, MA. State of incorporation: DE. Fiscal year ends December 31. SEC CIK 1701108.
SPRO board of directors & executives
From SEC Form 3/4/5 insider filings made in the last 12 months (date = latest filing).
Directors
| Name | Role | Latest filing |
|---|---|---|
| Milind Deshpande | Director | Jun 25, 2026 |
| Scott Thomas Jackson | Director | Jun 25, 2026 |
| John C Jr Pottage | Director | Jun 25, 2026 |
| Cynthia Smith | Director | Jun 25, 2026 |
| Frank E Thomas | Director | Jun 25, 2026 |
| Kathleen Tregoning | Director | Jun 25, 2026 |
| Patrick V.J.J. Vink | Director | Jun 25, 2026 |
Executive officers
| Name | Title | Latest filing |
|---|---|---|
| Timothy Keutzer | Chief Operating Officer | Feb 9, 2026 |
| Esther Rajavelu | See Remarks | May 6, 2026 |
| Debra Zack | Chief Medical Officer | Aug 6, 2026 |
Recent insider buys & sales
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| May 4, 2026 | Esther Rajavelu | Sale | 25,240 | $2.51 |
| May 4, 2026 | Esther Rajavelu | Sale | 25,240 | $2.51 |
| May 4, 2026 | Esther Rajavelu | Sale | 25,240 | $2.51 |
| May 4, 2026 | Esther Rajavelu | Sale | 25,240 | $2.51 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 37,101 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 50,816 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 37,101 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 50,816 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 37,101 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 50,816 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 37,101 | $2.36 |
| Feb 6, 2026 | Esther Rajavelu | Sale | 50,816 | $2.36 |
| Feb 6, 2026 | Timothy Keutzer | Sale | 18,652 | $2.36 |
| Feb 6, 2026 | Timothy Keutzer | Sale | 18,652 | $2.36 |
| Feb 6, 2026 | Timothy Keutzer | Sale | 18,652 | $2.36 |
SPRO financials (annual, from XBRL filings)
| Fiscal year end | Revenue | Net income | Diluted EPS | Operating cash flow |
|---|---|---|---|---|
| Dec 31, 2025 | $12.59M | $8.57M | 0.15 | $-12.62M |
| Dec 31, 2024 | $371.00K | $-68.57M | -1.27 | $-23.44M |
| Dec 31, 2023 | $933.00K | $22.81M | 0.43 | $-32.99M |
| Dec 31, 2022 | $2.50M | — | -1.23 | $-7.73M |
| Dec 31, 2021 | $3.07M | $-89.80M | -2.91 | $-64.35M |
Latest balance sheet: total assets $52.77M, total liabilities $8.56M, cash $50.77M (as of Jun 30, 2026).
SPRO earnings / results-day log
| Date | Filing | Close that day |
|---|---|---|
| Aug 12, 2026 | 8-K Item 2.02 (results) | $1.19 |
| May 13, 2026 | 8-K Item 2.02 (results) | $2.44 |
| Mar 26, 2026 | 8-K Item 2.02 (results) | $2.37 |
| Nov 13, 2025 | 8-K Item 2.02 (results) | $2.44 |
| Aug 12, 2025 | 8-K Item 2.02 (results) | $2.36 |
| May 13, 2025 | 8-K Item 2.02 (results) | $0.69 |
| Mar 27, 2025 | 8-K Item 2.02 (results) | $0.86 |
| Jan 10, 2025 | 8-K Item 2.02 (results) | $0.98 |
| Nov 14, 2024 | 8-K Item 2.02 (results) | $1.25 |
| Oct 29, 2024 | 8-K Item 2.02 (results) | $1.31 |
| Aug 5, 2024 | 8-K Item 2.02 (results) | — |
| May 15, 2024 | 8-K Item 2.02 (results) | — |
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Information only, not investment advice. BuyMeWhiskey is not a registered investment adviser or broker-dealer; nothing here is a recommendation to buy, sell or hold any security, and there are no price targets. Data comes from SEC EDGAR filings and public end-of-day market data and may be delayed or contain errors. Verify with the company's filings before making decisions. Prices: end-of-day data as of Oct 16, 2026, 4:00 PM ET. Filings: SEC EDGAR. Updated after every US trading day.