Stocks › CSTL
CASTLE BIOSCIENCES INC
CSTL·Nasdaq·
United States·USD
United States·USD$33.36
-3.29 (-8.98%)
Close · Oct 6, 2026 · Close Prices from Tiingo.com
CSTL
CASTLE BIOSCIENCES INC · Nasdaq
Nasdaq 100S&P 500
Filings
Default90D1Y5YALL
CSTLS&P 500 (rebased)
Congress BuyCongress SellInsider BuyInsider SellForm 1448-K ResultsLobbying
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Daily closes, adjusted for splits and dividends · Close Prices from Tiingo.comHover a marker, every one is a filing · move across the line for the crosshair
Congressional Trades
Recent trades of CSTL by members of U.S. Congress · 3 on record
| Politician | Stock | Type | Filed | Traded | |
|---|---|---|---|---|---|
 Josh GottheimerHouse · D · NJ |
CSTLCASTLE BIOSCIENCES INC · Stock |
Sale $1,001 - $15,000 |
Apr 17, 2022 | Mar 15, 2022 | Filing ↗ |
 Gilbert Ray Cisneros, Jr.House · D · CA |
CSTLCASTLE BIOSCIENCES INC · Stock |
Purchase $1,001 - $15,000 |
Jan 11, 2021 | Dec 23, 2020 | Filing ↗ |
| Josh GottheimerHouse · D · NJ |
CSTLCASTLE BIOSCIENCES INC · Stock |
Purchase $1,001 - $15,000 |
Jan 7, 2021 | Dec 21, 2020 | Filing ↗ |
Whale Activity
Position changes in CSTL reported for 2026-06-30 by 9 tracked institutional filers
- Increased3
- New1
- Held0
- Decreased5
- Closed0
- No prior filing0
| Filer | Shares | Value | Change |
|---|---|---|---|
| BlackRock, Inc. | 3.3M | $78.5M | increased |
| VANGUARD CAPITAL MANAGEMENT LLC | 1.2M | $29.3M | increased |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 840.8K | $20.1M | decreased |
| RENAISSANCE TECHNOLOGIES LLC | 371.2K | $8.9M | decreased |
| Point72 Asset Management, L.P. | 357.3K | $8.5M | new |
| CITADEL ADVISORS LLC | 265.4K | $6.3M | increased |
| MILLENNIUM MANAGEMENT LLC | 205.4K | $4.9M | decreased |
| D. E. Shaw & Co., Inc. | 112.8K | $2.7M | decreased |
| TWO SIGMA INVESTMENTS, LP | 100.4K | $2.4M | decreased |
KeyVex tracks a curated set of large 13F filers plus the largest positions in recent filings, so this is a sample of institutional activity, not the whole market.
Insider Trading
Net shares bought (+) or sold (−) on the open market by CSTL insiders, by quarter · Form 4
Recent Insider Transactions
2,744 transactions on record · newest first
| Insider | Type | Shares | Price | Value | Date | |
|---|---|---|---|---|---|---|
| Oelschlager Kristen MChief Operating Officer | Sale | −2,807 | $35.75 | $100K | Oct 1, 2026 | Form 4 ↗ |
| Oelschlager Kristen MChief Operating Officer | Sale | −1,346 | $36.38 | $49K | Oct 1, 2026 | Form 4 ↗ |
| Juvenal Tobin WChief Commercial Officer | Sale | −1,034 | $34.20 | $35K | Sep 30, 2026 | Form 4 ↗ |
| Juvenal Tobin WChief Commercial Officer | Sale | −5,543 | $35.50 | $197K | Sep 29, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −8,580 | $35.33 | $303K | Sep 21, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −3,198 | $35.33 | $113K | Sep 21, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −2,718 | $35.33 | $96K | Sep 21, 2026 | Form 4 ↗ |
| Juvenal Tobin WChief Commercial Officer | Sale | −3,294 | $35.14 | $116K | Sep 15, 2026 | Form 4 ↗ |
| Juvenal Tobin WChief Commercial Officer | Sale | −3,306 | $32.32 | $107K | Sep 14, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −8,361 | $32.00 | $268K | Sep 11, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −83 | $32.78 | $3K | Sep 11, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −71 | $32.78 | $2K | Sep 11, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −3,124 | $32.00 | $100K | Sep 11, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −2,656 | $32.00 | $85K | Sep 11, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −223 | $32.78 | $7K | Sep 11, 2026 | Form 4 ↗ |
| Oelschlager Kristen MChief Operating Officer | Sale | −3,952 | $33.36 | $132K | Sep 1, 2026 | Form 4 ↗ |
| Oelschlager Kristen MChief Operating Officer | Sale | −200 | $34.02 | $7K | Sep 1, 2026 | Form 4 ↗ |
| Juvenal Tobin WChief Commercial Officer | Sale | −1,730 | $32.81 | $57K | Aug 31, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −956 | $33.88 | $32K | Aug 28, 2026 | Form 4 ↗ |
| MAETZOLD DEREK JPres. & Chief Exec. Officer · Director | Sale | −257 | $33.14 | $9K | Aug 28, 2026 | Form 4 ↗ |
Fund Holders
Mutual funds and ETFs holding CSTL · SEC Form N-PORT
| Fund | Shares | Value | % of fund | As of |
|---|---|---|---|---|
| VANGUARD TOTAL STOCK MARKET INDEX FUND VANGUARD INDEX FUNDS | 852.7K | $20.3M | 0.00% | Jun 30, 2026 |
| SmallCap Fund Principal Funds, Inc | 725.1K | $20.3M | 0.97% | Jul 31, 2026 |
| iShares Russell 2000 ETF iShares Trust | 781.4K | $18.6M | 0.02% | Jun 30, 2026 |
| Eventide Healthcare & Life Sciences Fund MUTUAL FUND SERIES TRUST | 386.4K | $9.5M | 0.60% | Mar 31, 2026 |
| Fidelity Small Cap Index Fund Fidelity Salem Street Trust | 327.8K | $9.2M | 0.03% | Jul 31, 2026 |
| VANGUARD EXTENDED MARKET INDEX FUND VANGUARD INDEX FUNDS | 342.7K | $8.2M | 0.01% | Jun 30, 2026 |
| VANGUARD EXPLORER FUND | 275.9K | $7.7M | 0.03% | Jul 31, 2026 |
| iShares Russell 2000 Value ETF iShares Trust | 278.7K | $6.6M | 0.05% | Jun 30, 2026 |
| Wasatch Micro Cap Fund WASATCH FUNDS TRUST | 276.7K | $6.6M | 0.98% | Jun 30, 2026 |
| Strategic Advisers U.S. Total Stock Fund Fidelity Rutland Square Trust II | 312.1K | $6.6M | 0.01% | May 31, 2026 |
Mutual funds and ETFs whose N-PORT filings list CSTL's shares (CUSIP 14843C105), each fund at its latest report since Mar 7, 2026, largest positions first. Bonds, options and short positions are left out.
Activist & Passive Stakes
Schedule 13D / 13G beneficial-ownership filings
- Roderick WongSCHEDULE 13G/A · passive (13G) · 2.8M shares9.3%
May 15, 2026 · ↗ - RTW Investments, LPSCHEDULE 13G/A · passive (13G) · 2.8M shares9.3%
May 15, 2026 · ↗ - George McCabeSCHEDULE 13G/A · passive (13G) · 1.4M shares4.5%
May 15, 2026 · ↗ - Portolan Capital Management, LLCSCHEDULE 13G/A · passive (13G) · 1.4M shares4.5%
May 15, 2026 · ↗
Corporate Lobbying
Estimated quarterly lobbying spending reported under the LDA, filings naming castle biosciences as client
- MCDERMOTT+ LLCCASTLE BIOSCIENCES, INC. · 2026 Q2 · MMM$40K
Filing ↗ - MCDERMOTT+ LLCCASTLE BIOSCIENCES, INC. · 2026 Q1 · MMM$40K
Filing ↗ - MCDERMOTT+ LLCCASTLE BIOSCIENCES, INC. · 2025 Q4 · MMM$40K
Filing ↗ - MCDERMOTT+ LLCCASTLE BIOSCIENCES, INC. · 2025 Q3 · MMM$40K
Filing ↗ - MCDERMOTT+ LLCCASTLE BIOSCIENCES, INC. · 2025 Q2 · MMM$40K
Filing ↗
Government Contracts
Federal awards to castle biosciences · USAspending
$164KAwarded · 1 contract on record
- Department of Veterans AffairsGENE EXPRESSION PROFILE TESTING$164K
Sep 1, 2026 · ↗
U.S. Patents
Recent USPTO applications naming CASTLE BIOSCIENCES INC
No USPTO patent applications found for CASTLE BIOSCIENCES INC.
Annual Financials
From CSTL's 10-K filings · XBRL
No annual XBRL figures on record for CSTL. KeyVex's fundamentals cover about 130 large companies so far.
Stock Splits
Every split and reverse split in the price history
No stock splits in CSTL's price history.
About CASTLE BIOSCIENCES INC
From SEC EDGAR company records
Industry (SIC 8071)Services-Medical Laboratories
SectorHealthcare
HeadquartersFRIENDSWOOD, TX
IncorporatedDE
SEC CIK0001447362 ↗