Latest filingSep 03, 2026Most recent Form 4
CSTL
CASTLE BIOSCIENCES INC
NasdaqHealthcareServices-Medical Laboratories
Insider activity for last month from 08/03 to 09/03. Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.
Total buying$00 buys
Total selling$267M16 sells
Net open-market-$267M4 insiders
Open-market mix
Buy vs sell distribution by transaction countInsider activity report
Monthly open-market purchase and sale counts Buys Sells
Transaction codes
By Form 4 transaction code in selected period20transactions
- S · Open-market sells · dominant16 · 80%
- M · Option exercise4 · 20%
Activity by reported role
A joint filing can contribute to multiple roles30transactions
- Chief executive officer · dominant10 · 33%
- PRES10 · 33%
- COO7 · 23%
- CCO2 · 7%
- Chief financial officer1 · 3%
Distinct insiders active
Reporting-owner CIKs by month · peak Aug 2026 (4)Aug 2026Sep 2026
Reported Holdings After
Separated by insider, security, and ownership typeOelschlager Kristen MCommon Stock · Indirect · The Fritz Shorter Trust
77,872Aug 25, 2026
Maetzold Derek JCommon Stock · Direct
21,479Aug 28, 2026
Oelschlager Kristen MCommon Stock · Direct
13,356Sep 01, 2026
Juvenal Tobin WCommon Stock · Direct
66,914Aug 25, 2026
Maetzold Derek JCommon Stock · Indirect · By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk
11,277Aug 28, 2026
Maetzold Derek JCommon Stock · Indirect · By Derek Maetzold 2020 Irrevocable Trust
15,172Aug 28, 2026
Maetzold Derek JCommon Stock · Indirect · By The Maetzold Descendants 2020 Trust
17,850Aug 28, 2026
Stokes FrankCommon Stock · Direct
35,177Aug 14, 2026
These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.
Filing activity heatmap
Each cell is one day · intensity = transactions · buys green, sells redAug 03 → Sep 03
LessMore
Top insiders
By absolute net value across the selected period- SF-$741.5k
- MJ-$558.7k
- OM-$124.6k
- JW-$51.2k
Recent filing activity
Most recent 12 transactions · color = transaction codeFiling detail checks
Secondary metrics for the selected periodFiling-only signals
Deterministic matches in the selected period
CSTL transaction history
Filters apply within this company and selected period by default| Ticker | Insider | Role | Type | Shares | Value | Code | Signals | 90d return | Filed | Trans date |
|---|---|---|---|---|---|---|---|---|---|---|
| CSTL | Oelschlager Kristen M | COO | exercise10b5-1 | 4.15k | $0 | M | — | 0.0% | 09/03 | 09/01 |
| CSTL | Oelschlager Kristen M | COO | sale10b5-1 | 200 | -$680k | S | — | 0.0% | 09/03 | 09/01 |
| CSTL | Oelschlager Kristen M | COO | sale10b5-1 | 3.95k | -$13.1M | S | — | 0.0% | 09/03 | 09/01 |
| CSTL | Oelschlager Kristen M | COO | exercise10b5-1 | 4.15k | $1.40M | M | — | 0.0% | 09/03 | 09/01 |
| CSTL | MAETZOLD DEREK J | PRESCEO | exercise10b5-1 | 12.4k | $0 | M | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 21 | -$71.1k | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 177 | -$599k | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 209 | -$708k | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 956 | -$3.23M | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 257 | -$851k | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 2.12k | -$7.05M | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 2.50k | -$8.30M | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | sale10b5-1 | 11.4k | -$38.0M | S | 0.0% | 09/01 | 08/28 | |
| CSTL | MAETZOLD DEREK J | PRESCEO | exercise10b5-1 | 12.4k | $2.97M | M | 0.0% | 09/01 | 08/28 | |
| CSTL | Juvenal Tobin W | CCO | sale10b5-1 | 1.73k | -$5.11M | S | +3.5% | 08/19 | 08/17 | |
| CSTL | Stokes Frank | CFO | sale | 24.9k | -$74.1M | S | +15.2% | 08/18 | 08/14 |
CASTLE BIOSCIENCES INC Insider Activity FAQ
SEC Form 4 contextWho recently reported transactions at CASTLE BIOSCIENCES INC?
Oelschlager Kristen M, MAETZOLD DEREK J, Juvenal Tobin W, Stokes Frank.
When was the latest reported open-market purchase?
No code-P purchase is available for this period.
When was the latest reported open-market sale?
Oelschlager Kristen M reported a sale on Sep 01, 2026 valued at $680k. Read the SEC filing.
What is the recent purchase and sale balance?
Net open-market selling in the selected period was $2,674,769.45. Sales can occur for many non-investment reasons.
Where can I see the original SEC filing?
Every transaction row and latest-activity fact links to its original SEC filing.
What do these Form 4 transaction codes mean?
P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.