MRSNUnknownNano-Cap
Mersana Therapeutics, Inc. Insider Trading Activity
Every SEC Form 4 insider transaction reported for Mersana Therapeutics, Inc. (MRSN), sourced directly from SEC EDGAR and updated as new filings are accepted.
By Trabud · Insider-trading data from SEC EDGAR
Latest filing:
Compiled automatically from SEC EDGAR Form 4 filings and refreshed daily. Figures count purchases (code P) and sales (code S) only — not grants, option exercises, or gifts. How this page is built. Not investment advice.
Quick Answer
Are MRSN insiders buying or selling?
In the last 12 months, Mersana Therapeutics, Inc. insiders reported 0 open-market purchases ($0) and 1 sale ($762.3) — net selling of $762.3. Since July 2018, Trabud has recorded 93 Form 4 filings for MRSN: 15 buys ($76.8M) and 78 sells ($4.9M).
Source: SEC EDGAR Form 4
Key Statistics (July 2018 – Oct 28, 2025)
Total Form 4 filings
93
SEC EDGAR
Insider filers
18
Insider buys (15)
$76.8M
Insider sells (78)
$4.9M
Insider sentiment
Net buyingNet insider flow of $71.9M in net buying since July 2018, and $762.3 in net selling over the last 12 months.
Recent MRSN insider transactions
| Date | Insider | Role | Type | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Oct 28, 2025 | Mohan Bala | SVP, Chief Development Officer | Sale | 77 | $9.90 | $762.3 | SEC ↗ |
| Sep 15, 2025 | Martin H. Huber Jr. | President, CEO | Sale | 2.0K | $7.31 | $14.7K | SEC ↗ |
| Jan 18, 2025 | Ashish Mandelia | VP, Chief Accounting Officer | Sale | 3.6K | $0.58 | $2.1K | SEC ↗ |
| Jan 18, 2025 | Anna Protopapas | Director | Sale | 8.6K | $0.58 | $5.0K | SEC ↗ |
| Jan 18, 2025 | Timothy B Lowinger | SVP, Chief Sci.&Tech. Officer | Sale | 8.0K | $0.58 | $4.7K | SEC ↗ |
| Jan 18, 2025 | Martin H. Huber Jr. | President, CEO | Sale | 4.5K | $0.58 | $2.6K | SEC ↗ |
| Jan 18, 2025 | Brian Deschuytner | SVP, COO & CFO | Sale | 8.5K | $0.58 | $4.9K | SEC ↗ |
| Jan 18, 2025 | Alejandra Carvajal | SVP, Chief Legal Officer | Sale | 5.1K | $0.58 | $3.0K | SEC ↗ |
| Jan 18, 2025 | Mohan Bala | SVP, Chief Development Officer | Sale | 5.9K | $0.58 | $3.4K | SEC ↗ |
| Jan 16, 2025 | Anna Protopapas | Director | Sale | 6.2K | $0.63 | $3.9K | SEC ↗ |
| Jan 16, 2025 | Ashish Mandelia | VP, Chief Accounting Officer | Sale | 1.8K | $0.63 | $1.1K | SEC ↗ |
| Jan 16, 2025 | Timothy B Lowinger | SVP, Chief Sci.&Tech. Officer | Sale | 1.8K | $0.63 | $1.1K | SEC ↗ |
| Jan 16, 2025 | Brian Deschuytner | SVP, COO & CFO | Sale | 2.3K | $0.63 | $1.5K | SEC ↗ |
| Jan 16, 2025 | Alejandra Carvajal | SVP, Chief Legal Officer | Sale | 952 | $0.63 | $599.76 | SEC ↗ |
| Jan 16, 2025 | Anna Protopapas | Director | Sale | 11.5K | $0.66 | $7.6K | SEC ↗ |
| Jan 16, 2025 | Ashish Mandelia | VP, Chief Accounting Officer | Sale | 1.0K | $0.66 | $664.62 | SEC ↗ |
| Jan 16, 2025 | Timothy B Lowinger | SVP, Chief Sci.&Tech. Officer | Sale | 3.5K | $0.66 | $2.3K | SEC ↗ |
| Jan 16, 2025 | Brian Deschuytner | SVP, COO & CFO | Sale | 3.7K | $0.66 | $2.5K | SEC ↗ |
| Jan 16, 2025 | Alejandra Carvajal | SVP, Chief Legal Officer | Sale | 3.3K | $0.66 | $2.2K | SEC ↗ |
| Jan 16, 2025 | Mohan Bala | SVP, Chief Development Officer | Sale | 3.3K | $0.66 | $2.1K | SEC ↗ |
| Oct 29, 2024 | Mohan Bala | SVP, Chief Development Officer | Sale | 1.9K | $1.90 | $3.6K | SEC ↗ |
| Oct 7, 2024 | Brian Deschuytner | SVP, COO & CFO | Sale | 13.7K | $1.98 | $27.2K | SEC ↗ |
| Oct 7, 2024 | Alejandra Carvajal | SVP, Chief Legal Officer | Sale | 13.7K | $1.98 | $27.2K | SEC ↗ |
| Oct 7, 2024 | Mohan Bala | SVP, Chief Development Officer | Sale | 13.7K | $1.98 | $27.2K | SEC ↗ |
| Oct 7, 2024 | Ashish Mandelia | VP, Chief Accounting Officer | Sale | 8.2K | $1.98 | $16.3K | SEC ↗ |
Showing the 25 most recent of 93 Form 4 filings for Mersana Therapeutics, Inc..
Most active MRSN insiders
- Timothy B Lowinger24 filings
- Ashish Mandelia10 filings
- F. A. Hack Andrew10 filings
- Alejandra Carvajal8 filings
- Anna Protopapas6 filings
Ask anything about MRSN insider activity
Use Trabud's AI agent to query Mersana Therapeutics, Inc.'s Form 4 history in plain English — "Show me MRSN CEO purchases this year" or compare it against any other ticker.
Open the AI agentMRSN insider trading FAQ
Are Mersana Therapeutics, Inc. insiders buying or selling?
In the last 12 months, Mersana Therapeutics, Inc. insiders reported 0 open-market purchases ($0) and 1 sale ($762.3) — net selling of $762.3. Since July 2018, Trabud has recorded 93 Form 4 filings for MRSN: 15 buys ($76.8M) and 78 sells ($4.9M). Over the full record that is net buying of $71.9M.
How many insiders trade MRSN stock?
18 distinct insider filers — officers, directors, 10%+ owners, and investment groups filing jointly — have reported Form 4 transactions for Mersana Therapeutics, Inc.. The most recent filing was accepted on Oct 28, 2025.
Where does Trabud get MRSN insider trading data?
All MRSN insider trading data comes directly from official SEC EDGAR Form 4 filings, which corporate insiders must submit within two business days of a transaction under Section 16(a) of the Securities Exchange Act of 1934.