Robert W. Hesslein
CIK 1585018 · EVP, CLO and Secretary · last filed 2025-03-05
Robert W. Hesslein is an EVP, CLO and Secretary who has filed 45 SEC Form 4 insider transactions across 3 companies since 2014. The most recent filing, for ALNY, was dated Mar 5, 2025. Across all open-market trades the lifetime net is −$3.7M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $2.0M across reported positions. 3 SEC filings were submitted jointly with ALNYLAM PHARMACEUTICALS, INC.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
Charts
Trading activity, where the exposure sits, and each trade against the stock price.
FMI price and trades
Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.
Shares held
Shares owned after each reported transaction on this company (direct holdings as reported).
Open-market buying and selling
by monthDollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.
Exposure by company
latestMost recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.
Filer Profile
ONE KENDALL SQUARE, SUITE B3501
CAMBRIDGE, MA 02139
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| ALNY | EVP, CLO and Secretary | 8,002 | $231.83 | $1.86M | $0 | 2 | 2025-03-05 |
| VYGR | Senior VP & General Counsel | 102,200 | $1.90 | $194.2K | -$226.0K | 16 | 2023-03-22 |
| Foundation Medicine, Inc. (FMI) Delisted | SVP and General Counsel | 105,203 | — | — | -$3.43M | 26 | 2018-07-05 |
Recent Filings
45 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2025-03-05 | ALNY | Grant (A) | +757 | $0 | EDGAR |
| 2024-10-03 | ALNY | Grant (A) | +7,245 | $0 | EDGAR |
| 2023-03-22 | VYGR | Sell (S) | −4,410 | -$34.2K | EDGAR |
| 2023-02-22 | VYGR | Sell (S) | −3,297 | -$24.6K | EDGAR |
| 2023-02-15 | VYGR | Sell (S) | −2,868 | -$22.0K | EDGAR |
| 2023-01-19 | VYGR | Sell (S) | −2,188 | -$21.5K | EDGAR |
| 2022-04-06 | VYGR | Sell (S) | −2,786 | -$23.0K | EDGAR |
| 2022-03-23 | VYGR | Sell (S) | −4,955 | -$41.1K | EDGAR |
| 2022-02-22 | VYGR | Sell (S) | −4,100 | -$14.6K | EDGAR |
| 2022-02-15 | VYGR | Sell (S) | −3,252 | -$10.9K | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.