William Mariner Greenman
CIK 1377258 · President and CEO · last filed 2026-07-02
"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.
CERS 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
2411 STANWELL DRIVE
CONCORD, CA 94520
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| CERS | President and CEO | 5,154,955 | $2.39 | $12.32M | -$6.47M | 61 | 2026-07-02 |
| CHINOOK THERAPEUTICS, INC. (KDNY) Delisted | Director | 0 | $40.39 | $0 | -$26.9K | 6 | 2023-08-11 |
| CHINOOK THERAPEUTICS, INC. (ADRO) Delisted | Director | 19,835 | — | — | -$41.0K | 9 | 2020-05-28 |
Recent Filings · Page 6 of 8
76 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2015-03-04 | CERS | Grant (A) | — | $0 | EDGAR |
| 2014-11-12 | CERS | Buy (P) | +21,800 | $85.6K | EDGAR |
| 2014-03-28 | CERS | Exer (M) | +50 | $176 | EDGAR |
| 2014-03-04 | CERS | Mixed | +53,500 | $122.0K | EDGAR |
| 2014-03-04 | CERS | Mixed | +53,500 | $122.0K | EDGAR |
| 2013-08-23 | CERS | Exer (M) | +17,250 | $73.3K | EDGAR |
| 2013-03-05 | CERS | Grant (A) | — | $0 | EDGAR |
| 2013-01-09 | CERS | Other (J) | −2,866 | -$8.5K | EDGAR |
| 2012-11-20 | CERS | Buy (P) | +3,200 | $9.7K | EDGAR |
| 2012-11-16 | CERS | Buy (P) | +13,800 | $39.4K | 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.