OTC · CIK 0001527599
SYBX SYNLOGIC, INC.
Insider trading from SEC Form 4. Last filing Oct 31, 2025. Close $1.10 on Oct 9, 2026, +96% from the 52-week low and -40% from the high.
SYNLOGIC, INC. (SYBX) has 6 SEC Form 4 filings on file from 3 insiders, the latest filed on Oct 31, 2025. No insider bought or sold on the open market in the last 90 days; rows filed in that time are grants, exercises, tax withholding and other transactions that carry no view on the price.
4 open-market trades have been scored at SYBX. The newest: Mary Beth Dooley (See Remarks below) sold $284 of stock on Oct 29, 2025, filed Oct 31, 2025, scored 15 (weak). The largest of the 4 shown: Mary Beth Dooley (See Remarks below) sold $2,802 on Feb 3, 2025, scored 20 (weak).
SYBX closed at $1.10 on Oct 9, 2026, 96% above its 52-week low and 40% below its 52-week high.
Last 90 days
Price and insider trades, last year
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value. Click a marked bar to open the signal.Charts by TradingView Lightweight Charts™
Signals
Open-market buys and sells at SYNLOGIC, INC., scored.
| Score | Insider | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 15Weak | Mary Beth Dooley See Remarks below sell | $284 157 shares | -1% | +82% from low-3% from high | |
| 15Weak | Mary Beth Dooley See Remarks below sell | $173 144 shares | -1% | 0% from low-29% from high | |
| 20Weak | Mary Beth Dooley See Remarks below sell | $2,802 2,107 shares | -14% | - | |
| 15Weak | Mary Beth Dooley Head of Finance sell | $111 79 shares | -1% | - |
Transactions
Every row filed, 6 in all.
| Date | Insider | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Oct 29, 2025 | Mary Beth Dooley See Remarks below | SOpen-market sale Common Stock | -157 | $1.81 | $284 | 12,744 | Oct 31, 2025 |
| Apr 26, 2025 | James P Flynn director | AGrant or award Common Stock | +15,000 | $0.00 | $0 | 15,000 | Apr 29, 2025 |
| Apr 26, 2025 | Richard P Shea director | AGrant or award Common Stock | +15,000 | $0.00 | $0 | 15,506 | Apr 29, 2025 |
| Apr 2, 2025 | Mary Beth Dooley See Remarks below | SOpen-market sale Common Stock | -144 | $1.20 | $173 | 12,901 | Apr 3, 2025 |
| Feb 3, 2025 | Mary Beth Dooley See Remarks below | SOpen-market sale Common Stock | -2,107 | $1.33 | $2,802 | 13,045 | Feb 4, 2025 |
| Oct 29, 2024 | Mary Beth Dooley Head of Finance | SOpen-market sale Common Stock | -79 | $1.40 | $111 | 15,152 | Oct 30, 2024 |
Insiders
Everyone who has filed a Form 4 here.
- Mary Beth DooleySee Remarks below
- James P Flynndirector
- Richard P Sheadirector
Questions about SYBX
Answered from the filings on this page, as of the latest one.
Are insiders buying SYBX?
No. In the last 90 days no insider at SYNLOGIC, INC. bought or sold shares on the open market according to SEC Form 4 filings. The rows on file from that period are grants, exercises, tax withholding or other transactions, which carry no view on the price.
Who was the last insider to trade SYBX on the open market?
Mary Beth Dooley (See Remarks below) sold $284 of SYBX on Oct 29, 2025 and filed the Form 4 on Oct 31, 2025. InsiderTell scored 15 (weak).
How many insiders file Form 4 at SYNLOGIC, INC.?
3 people have filed a Form 4 at SYNLOGIC, INC., among them Mary Beth Dooley (See Remarks below), James P Flynn (director), Richard P Shea (director). Officers, directors and holders of more than 10% of a share class must report their trades within two business days.
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.