Sionna Therapeutics (SION) Stock Analysis & Price (Updated Oct 16, 2026, 4:00 PM ET)
Updated Oct 16, 2026, 4:00 PM ET
- Closed at $3.89, -4.66% vs the prior close of $4.08.
- Volume 1.48M 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.
SION slides 4.7% to $3.89, a 52-week low, 6 down days in a row. Closed at $3.89, -4.66% vs the prior close of $4.08. Day range $3.78–$4.06, opened at $4.06.
SION 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 — SION slides 4.7% to $3.89, a 52-week low, 6 down days in a row
- Closed at $3.89, -4.66% vs the prior close of $4.08. Day range $3.78–$4.06, opened at $4.06.
- Volume was 1.48M shares, 0.6x its 50-day average of 2.67M — lighter than usual.
- Price is -42.3% vs its 50-day average ($6.74) and -87.8% vs its 200-day average ($31.87).
- 52-week range $3.78–$54.97; today's close sits at 0% of that range, 92.9% below the 52-week high.
- That makes 6 straight losses.
Oct 15, 2026 — SION ends flat (-0.2%) to $4.08, a 52-week low, 5 down days in a row
- Closed at $4.08, -0.24% vs the prior close of $4.09. Day range $4.02–$4.30, opened at $4.15.
- Volume was 944.60K shares, 0.4x its 50-day average of 2.66M — lighter than usual.
- Price is -46.7% vs its 50-day average ($7.65) and -87.3% vs its 200-day average ($32.06).
- 52-week range $3.93–$54.97; today's close sits at 0% of that range, 92.6% below the 52-week high.
- That makes 5 straight losses.
Oct 14, 2026 — SION slides 6.6% to $4.09, a 52-week low, 4 down days in a row
- Closed at $4.09, -6.62% vs the prior close of $4.38. Day range $3.93–$4.40, opened at $4.30.
- Volume was 1.50M shares, 0.6x its 50-day average of 2.65M — lighter than usual.
- Price is -52.0% vs its 50-day average ($8.52) and -87.3% vs its 200-day average ($32.25).
- 52-week range $3.93–$54.97; today's close sits at 0% of that range, 92.6% below the 52-week high.
- That makes 4 straight losses.
Oct 13, 2026 — SION slides 6.6% to $4.38, a 52-week low, 3 down days in a row
- Closed at $4.38, -6.61% vs the prior close of $4.69. Day range $4.36–$4.80, opened at $4.69.
- Volume was 790.40K shares, 0.3x its 50-day average of 2.65M — lighter than usual.
- Price is -53.6% vs its 50-day average ($9.44) and -86.5% vs its 200-day average ($32.45).
- 52-week range $4.01–$54.97; today's close sits at 1% of that range, 92.0% below the 52-week high.
- That makes 3 straight losses.
Oct 12, 2026 — SION slides 4.3% to $4.69, a 1-month low
- Closed at $4.69, -4.29% vs the prior close of $4.90. Day range $4.68–$4.93, opened at $4.89.
- Volume was 692.50K shares, 0.3x its 50-day average of 2.64M — lighter than usual.
- Price is -54.6% vs its 50-day average ($10.33) and -85.6% vs its 200-day average ($32.65).
- 52-week range $4.01–$54.97; today's close sits at 1% of that range, 91.5% below the 52-week high.
Oct 9, 2026 — SION ends flat (+0.0%) to $4.90
- Closed at $4.90, +0.00% vs the prior close of $4.90. Day range $4.83–$5.12, opened at $4.93.
- Volume was 633.60K shares, 0.2x its 50-day average of 2.63M — lighter than usual.
- Price is -56.2% vs its 50-day average ($11.18) and -85.1% vs its 200-day average ($32.84).
- 52-week range $4.01–$54.97; today's close sits at 2% of that range, 91.1% below the 52-week high.
Oct 8, 2026 — SION rises 1.7% to $4.90
- Closed at $4.90, +1.66% vs the prior close of $4.82. Day range $4.65–$4.97, opened at $4.78.
- Volume was 915.60K shares, 0.3x its 50-day average of 2.62M — lighter than usual.
- Price is -59.2% vs its 50-day average ($12.02) and -85.2% vs its 200-day average ($33.03).
- 52-week range $4.01–$54.97; today's close sits at 2% of that range, 91.1% below the 52-week high.
Oct 7, 2026 — SION rises 1.5% to $4.82
- Closed at $4.82, +1.47% vs the prior close of $4.75. Day range $4.61–$4.87, opened at $4.68.
- Volume was 880.10K shares, 0.3x its 50-day average of 2.61M — lighter than usual.
- Price is -62.4% vs its 50-day average ($12.82) and -85.5% vs its 200-day average ($33.22).
- 52-week range $4.01–$54.97; today's close sits at 2% of that range, 91.2% below the 52-week high.
Oct 6, 2026 — SION dips 2.1% to $4.75, a 1-month low, 4 down days in a row
- Closed at $4.75, -2.06% vs the prior close of $4.85. Day range $4.52–$4.88, opened at $4.88.
- Volume was 1.26M shares, 0.5x its 50-day average of 2.60M — lighter than usual.
- Price is -65.2% vs its 50-day average ($13.65) and -85.8% vs its 200-day average ($33.41).
- 52-week range $4.01–$54.97; today's close sits at 1% of that range, 91.4% below the 52-week high.
- That makes 4 straight losses.
Oct 5, 2026 — SION dips 1.2% to $4.85, a 1-month low, 3 down days in a row
- Closed at $4.85, -1.22% vs the prior close of $4.91. Day range $4.63–$4.96, opened at $4.95.
- Volume was 1.10M shares, 0.4x its 50-day average of 2.59M — lighter than usual.
- Price is -66.5% vs its 50-day average ($14.46) and -85.6% vs its 200-day average ($33.61).
- 52-week range $4.01–$54.97; today's close sits at 2% of that range, 91.2% below the 52-week high.
- That makes 3 straight losses.
Oct 2, 2026 — SION slides 3.7% to $4.91, a 1-month low
- Closed at $4.91, -3.73% vs the prior close of $5.10. Day range $4.86–$5.19, opened at $5.19.
- Volume was 1.16M shares, 0.4x its 50-day average of 2.58M — lighter than usual.
- Price is -67.9% vs its 50-day average ($15.28) and -85.5% vs its 200-day average ($33.80).
- 52-week range $4.01–$54.97; today's close sits at 2% of that range, 91.1% below the 52-week high.
SION latest news & SEC filings
Every SEC filing by or about SION in the last 120 days, explained in plain English. Updated daily, with a same-day refresh for new filings.
Sep 21, 2026 · Form SCHEDULE 13D/A — Update to a 13D 5%+ stake disclosure
Update to a 13D 5%+ stake disclosure
Filed by an outside investor (not the company). It reports a holding of more than 5% of a share class; percentage and holder name are in the filing.
Sep 21, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Ra Capital Management, L.P. & Ra Capital Healthcare Fund Lp & Ra Capital Nexus Fund, L.P. & Ra Capital Nexus Fund Iii, L.P. & Kolchinsky Peter & Shah Rajeev M. sold 3,415,011 shares at $6.32 (≈$21.58M) on Sep 17, 2026; now holds 3,482,612
- Ra Capital Management, L.P. & Ra Capital Healthcare Fund Lp & Ra Capital Nexus Fund, L.P. & Ra Capital Nexus Fund Iii, L.P. & Kolchinsky Peter & Shah Rajeev M. sold 33,800 shares at $7.46 (≈$252.15K) on Sep 17, 2026; now holds 3,448,812
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Sep 18, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Ridloff Elena received an award of 47,269 shares on Sep 17, 2026; now holds 85,801
- Ridloff Elena received an award of 47,268 shares on Sep 17, 2026; now holds 133,069
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Sep 18, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Mckee Charlotte received an award of 50,000 shares on Sep 17, 2026; now holds 78,415
- Mckee Charlotte received an award of 50,000 shares on Sep 17, 2026; now holds 128,415
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Sep 18, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Fitzpatrick Jennifer received an award of 28,133 shares on Sep 17, 2026; now holds 28,133
- Fitzpatrick Jennifer received an award of 28,132 shares on Sep 17, 2026; now holds 56,265
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Sep 18, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Cloonan Michael received an award of 109,025 shares on Sep 17, 2026; now holds 656,368
- Cloonan Michael received an award of 109,025 shares on Sep 17, 2026; now holds 765,393
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Sep 17, 2026 · Form 144 — Planned insider sale
Notice of proposed sale (Form 144) — an insider or affiliate plans to sell restricted or control shares
A notice of intent, not a completed sale. Any actual sale by a director or officer shows up later on Form 4.
Sep 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 2.05 — Costs tied to exiting activities / restructuring.
- Item 5.02 — Change in directors or officers (appointment, departure or pay).
- Item 8.01 — Reported other events the company considers important.
Aug 10, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 8.01 — Reported other events the company considers important.
Aug 6, 2026 · Form 10-Q — Quarterly report
Quarterly report (unaudited financial statements for the quarter)
Quarter ended Jun 30, 2026:
- Net income: -$29.89M (prior year -$18.07M) (loss widened vs Jun 30, 2025)
- Diluted EPS: -$0.66 (prior year -$0.41) (loss widened vs Jun 30, 2025)
Aug 6, 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.
Things to know before you trade SION
- Last results release: Aug 6, 2026 (8-K Item 2.02). Previous ones: May 12, 2026, Mar 2, 2026, Nov 5, 2025. Based on that rhythm, the next report is likely around Nov 5, 2026 — an estimate, not a confirmed date.
- How much it moves: over the last 20 sessions the average daily move was 2.75% (largest 8.5%).
- Liquidity: about 1.18M shares (≈$4.60M) trade per day on average.
- 52-week position: $3.89 vs a range of $3.78–$54.97 (0% 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: Capital Management, L.P. Ra sold 3,415,011 shares on Sep 17, 2026.
- Latest filings: 8-K Sep 14, 2026; 8-K Aug 10, 2026; 10-Q Aug 6, 2026.
- Share count: 45.21M shares outstanding (Jul 31, 2026), +2.4% vs a year earlier.
- Listing: Nasdaq · industry: Pharmaceutical Preparations.
SION market data (last 20 sessions)
| Date | Open | High | Low | Close | Volume |
|---|---|---|---|---|---|
| Oct 16, 2026 | 4.06 | 4.06 | 3.78 | 3.89 | 1.48M |
| Oct 15, 2026 | 4.15 | 4.30 | 4.02 | 4.08 | 944.60K |
| Oct 14, 2026 | 4.30 | 4.40 | 3.93 | 4.09 | 1.50M |
| Oct 13, 2026 | 4.69 | 4.80 | 4.36 | 4.38 | 790.40K |
| Oct 12, 2026 | 4.89 | 4.93 | 4.68 | 4.69 | 692.50K |
| Oct 9, 2026 | 4.93 | 5.12 | 4.83 | 4.90 | 633.60K |
| Oct 8, 2026 | 4.78 | 4.97 | 4.65 | 4.90 | 915.60K |
| Oct 7, 2026 | 4.68 | 4.87 | 4.61 | 4.82 | 880.10K |
| Oct 6, 2026 | 4.88 | 4.88 | 4.52 | 4.75 | 1.26M |
| Oct 5, 2026 | 4.95 | 4.96 | 4.63 | 4.85 | 1.10M |
| Oct 2, 2026 | 5.19 | 5.19 | 4.86 | 4.91 | 1.16M |
| Oct 1, 2026 | 5.26 | 5.33 | 5.03 | 5.10 | 1.06M |
| Sep 30, 2026 | 5.19 | 5.34 | 5.02 | 5.26 | 1.16M |
| Sep 29, 2026 | 5.15 | 5.19 | 5.03 | 5.15 | 797.50K |
| Sep 28, 2026 | 5.17 | 5.25 | 5.05 | 5.12 | 775.60K |
| Sep 25, 2026 | 5.28 | 5.30 | 5.09 | 5.23 | 1.40M |
| Sep 24, 2026 | 5.50 | 5.59 | 5.15 | 5.23 | 1.25M |
| Sep 23, 2026 | 6.03 | 6.12 | 5.32 | 5.51 | 1.67M |
| Sep 22, 2026 | 5.99 | 6.17 | 5.84 | 6.02 | 1.69M |
| Sep 21, 2026 | 6.00 | 6.13 | 5.70 | 6.00 | 2.52M |
About Sionna Therapeutics
Sionna Therapeutics (SION) is listed on the Nasdaq and classified by the SEC under “Pharmaceutical Preparations”. Its business address is in WALTHAM, MA. State of incorporation: DE. Fiscal year ends December 31. SEC CIK 2036042.
SION 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 |
|---|---|---|
| Bruce Booth | Director | Jun 18, 2026 |
| Paul J Clancy | Director | Jun 18, 2026 |
| Michael Cloonan | President & CEO | Sep 18, 2026 |
| Harold Edward Fleming | Director | Jun 18, 2026 |
| Peter Kolchinsky | Director | Sep 21, 2026 |
| Advisors Llc Orbimed | Director | Jul 9, 2026 |
| Capital Gp Viii Llc Orbimed | Director | Jul 9, 2026 |
| Capital Management, L.P. Ra | Director | Sep 21, 2026 |
| Capital Healthcare Fund Lp Ra | Director | Sep 21, 2026 |
| Capital Nexus Fund Iii, L.P. Ra | Director | Sep 21, 2026 |
| Capital Nexus Fund, L.P. Ra | Director | Sep 21, 2026 |
| Joshua Resnick | Director | Jun 18, 2026 |
| Marcella K. Ruddy | Director | Jun 18, 2026 |
| Rajeev M. Shah | Director | Sep 21, 2026 |
| Laurie Stelzer | Director | Jun 18, 2026 |
| Peter A. Thompson | Director | Jul 9, 2026 |
| Joanne L. Viney | Director | Jun 18, 2026 |
Executive officers
| Name | Title | Latest filing |
|---|---|---|
| Caroline Stark Beer | Chief Business Officer | Jan 6, 2026 |
| Michael Cloonan | President & CEO | Sep 18, 2026 |
| Jennifer Fitzpatrick | CLO and Head of Program Mgmt. | Sep 18, 2026 |
| Charlotte Mckee | CMO and Head of R&D | Sep 18, 2026 |
| Elena Ridloff | CFO and CBO | Sep 18, 2026 |
Recent insider buys & sales
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Sep 17, 2026 | Capital Management, L.P. Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Management, L.P. Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Capital Management, L.P. Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Management, L.P. Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Capital Healthcare Fund Lp Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Healthcare Fund Lp Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Capital Healthcare Fund Lp Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Healthcare Fund Lp Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Capital Nexus Fund Iii, L.P. Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Nexus Fund Iii, L.P. Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Capital Nexus Fund Iii, L.P. Ra | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Capital Nexus Fund Iii, L.P. Ra | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Rajeev M. Shah | Sale | 3,415,011 | $6.32 |
| Sep 17, 2026 | Rajeev M. Shah | Sale | 33,800 | $7.46 |
| Sep 17, 2026 | Rajeev M. Shah | Sale | 3,415,011 | $6.32 |
SION financials (annual, from XBRL filings)
| Fiscal year end | Revenue | Net income | Diluted EPS | Operating cash flow |
|---|---|---|---|---|
| Dec 31, 2025 | — | $-75.27M | -1.88 | $-66.30M |
| Dec 31, 2024 | — | $-61.69M | -15.99 | $-52.79M |
Latest balance sheet: total assets $283.25M, total liabilities $17.47M, cash $63.32M (as of Jun 30, 2026).
SION earnings / results-day log
| Date | Filing | Close that day |
|---|---|---|
| Aug 6, 2026 | 8-K Item 2.02 (results) | $49.61 |
| May 12, 2026 | 8-K Item 2.02 (results) | $40.94 |
| Mar 2, 2026 | 8-K Item 2.02 (results) | $33.92 |
| Nov 5, 2025 | 8-K Item 2.02 (results) | $35.08 |
| Aug 11, 2025 | 8-K Item 2.02 (results) | $20.03 |
| May 12, 2025 | 8-K Item 2.02 (results) | $12.90 |
| Mar 20, 2025 | 8-K Item 2.02 (results) | $13.88 |
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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.