DEREK J MAETZOLD
CIK 1239501 · Pres. & Chief Exec. Officer · last filed 2026-08-06
"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.
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Disclosed Exposure
$1.99M
Companies
2
Total Filings
225
Lifetime Open-Market Net
-$93.87M
Holdings By Company
Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| CSTL | Pres. & Chief Exec. Officer | 65,051 | $30.55 | $1.99M | -$93.87M | 191 | 2026-08-06 |
| ENCYSIVE PHARMACEUTICALS INC (ENCY) Delisted | V.P., Marketing & Sales | 0 | — | — | $0 | 4 | 2008-04-03 |
Recent Filings · Page 5 of 23
225 filingsInsider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2025-10-23 | CSTL | Sell (S) | −1,339 | -$30.0K | EDGAR |
| 2025-10-06 | CSTL | Sell (S) | −1,339 | -$30.2K | EDGAR |
| 2025-10-02 | CSTL | Notice (144) | −4,017 | -$89.3K | EDGAR |
| 2025-09-19 | CSTL | Sell (S) | −1,339 | -$29.4K | EDGAR |
| 2025-09-04 | CSTL | Sell (S) | −1,339 | -$32.0K | EDGAR |
| 2025-08-19 | CSTL | Sell (S) | −1,339 | -$26.8K | EDGAR |
| 2025-08-15 | CSTL | Notice (144) | −4,017 | -$80.7K | EDGAR |
| 2025-08-15 | CSTL | Sell (S) | −43,019 | -$839.0K | EDGAR |
| 2025-08-13 | CSTL | Notice (144) | −43,019 | -$835.0K | EDGAR |
| 2025-08-12 | CSTL | Mixed | +43,019 | -$464.1K | EDGAR |
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
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.
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.