Insider · CIK 0002071593
John D Duke
Files at HBIO (HARVARD BIOSCIENCE INC). First filing Mar 17, 2026, latest Mar 17, 2026.
In brief
John D Duke files SEC Form 4 as CEO and director at HBIO (HARVARD BIOSCIENCE INC). Since Mar 17, 2026, John D Duke has reported 1 open-market buy worth $25k and 0 open-market sells worth $0, the latest filed on Mar 17, 2026.
A track record needs three past buys with six months of prices behind them; John D Duke has 0, so none is measured yet.
The newest scored trade: bought $25k of HBIO on Mar 16, 2026, filed Mar 17, 2026, scored 56 (moderate). In the last 12 months: 1 buy worth $25k and 0 sells worth $0.
Where the trades landed
Last year at the company this insider has traded most, with each buy and sell on the bar it happened.
HBIO: HARVARD BIOSCIENCE INC
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
This insider’s open-market buys and sells, scored.
| Score | Company | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 56Moderate | HARVARD BIOSCIENCE INC | $25k 5,000 shares | +5% | +79% from low-37% from high |
Transactions
Every row this insider has filed, 4 in all, newest first.
| Date | Company | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Mar 20, 2026 | HBIO HARVARD BIOSCIENCE INC | AGrant or award Common Stock | +75,000 | $0.00 | $0 | 180,000 | Mar 23, 2026 |
| Mar 16, 2026 | HBIO HARVARD BIOSCIENCE INC | POpen-market purchase Common Stock | +5,000 | $5.01 | $25k | 105,000 | Mar 17, 2026 |
| Aug 8, 2025 | HBIO HARVARD BIOSCIENCE INC | AGrant or award Common Stock | +500,000 | $0.00 | $0 | 500,000 | Aug 11, 2025 |
| Aug 8, 2025 | HBIO HARVARD BIOSCIENCE INC | AGrant or award Common Stock | +500,000 | $0.00 | $0 | 1,000,000 | Aug 11, 2025 |
Questions about John D Duke
Answered from the filings on this page, as of the latest one.
Is John D Duke buying or selling?
In the last 12 months John D Duke reported 1 open-market buy worth $25k and 0 open-market sells worth $0 on SEC Form 4; the latest was bought $25k of HBIO on Mar 16, 2026. Grants, option exercises and tax withholding are not counted.
How did John D Duke's past buys perform?
Not measured yet. InsiderTell needs three past buys with six months of prices to publish a track record, and John D Duke has 0.
Where does John D Duke file Form 4?
John D Duke has filed Form 4 at HBIO (HARVARD BIOSCIENCE INC) as Chief Executive Officer. A Form 4 is required of officers, directors and holders of more than 10% of a share class within two business days of a trade.
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.