Castle Biosciences (CSTL) Latest Stock Analysis Report – Oct 15, 2026, 4:00 PM ET
Updated Oct 15, 2026, 4:00 PM ET
- Closed at $33.80, +2.08% vs the prior close of $33.11.
- Volume 381.90K shares, 1.0x its 50-day average.
- New SEC filings: 4 (Oct 14, 2026).
- No new insider buys or sales reported since the prior session.
CSTL rises 2.1% to $33.80, 3 up days in a row. Closed at $33.80, +2.08% vs the prior close of $33.11. Day range $32.48–$34.06, opened at $33.13.
CSTL daily analysis — what happened
A plain-English, data-only note written after every US trading day. Newest first; older days stay archived below.
Oct 15, 2026 — CSTL rises 2.1% to $33.80, 3 up days in a row
- Closed at $33.80, +2.08% vs the prior close of $33.11. Day range $32.48–$34.06, opened at $33.13.
- Volume was 381.90K shares, 1.0x its 50-day average of 367.92K.
- Price is +0.9% vs its 50-day average ($33.51) and +17.3% vs its 200-day average ($28.81).
- 52-week range $17.72–$44.28; today's close sits at 61% of that range, 23.7% below the 52-week high.
- That makes 3 straight gains.
Oct 14, 2026 — CSTL rises 0.7% to $33.11
- Closed at $33.11, +0.70% vs the prior close of $32.88. Day range $32.47–$33.77, opened at $32.47.
- Volume was 243.20K shares, 0.6x its 50-day average of 376.55K.
- Price is -1.0% vs its 50-day average ($33.45) and +14.8% vs its 200-day average ($28.84).
- 52-week range $17.72–$44.28; today's close sits at 58% of that range, 25.2% below the 52-week high.
Oct 13, 2026 — CSTL rises 0.4% to $32.88
- Closed at $32.88, +0.37% vs the prior close of $32.76. Day range $32.23–$33.35, opened at $32.79.
- Volume was 241.70K shares, 0.6x its 50-day average of 387.40K.
- Price is -1.6% vs its 50-day average ($33.41) and +13.9% vs its 200-day average ($28.87).
- 52-week range $17.72–$44.28; today's close sits at 57% of that range, 25.7% below the 52-week high.
Oct 12, 2026 — CSTL slides 4.8% to $32.76
- Closed at $32.76, -4.82% vs the prior close of $34.42. Day range $32.31–$34.42, opened at $34.42.
- Volume was 239.00K shares, 0.6x its 50-day average of 417.77K — lighter than usual.
- Price is -1.8% vs its 50-day average ($33.36) and +13.3% vs its 200-day average ($28.91).
- 52-week range $17.72–$44.28; today's close sits at 57% of that range, 26.0% below the 52-week high.
Oct 9, 2026 — CSTL rises 2.1% to $34.42
- Closed at $34.42, +2.11% vs the prior close of $33.71. Day range $33.39–$34.52, opened at $33.52.
- Volume was 249.10K shares, 0.6x its 50-day average of 427.12K — lighter than usual.
- Price is +3.5% vs its 50-day average ($33.26) and +18.9% vs its 200-day average ($28.95).
- 52-week range $17.72–$44.28; today's close sits at 63% of that range, 22.3% below the 52-week high.
Oct 8, 2026 — CSTL rises 2.2% to $33.71
- Closed at $33.71, +2.15% vs the prior close of $33.00. Day range $32.25–$33.76, opened at $32.54.
- Volume was 373.80K shares, 0.9x its 50-day average of 426.44K.
- Price is +1.8% vs its 50-day average ($33.11) and +16.3% vs its 200-day average ($28.98).
- 52-week range $17.72–$44.28; today's close sits at 60% of that range, 23.9% below the 52-week high.
Oct 7, 2026 — CSTL dips 1.1% to $33.00
- Closed at $33.00, -1.08% vs the prior close of $33.36. Day range $32.77–$33.72, opened at $33.15.
- Volume was 351.50K shares, 0.8x its 50-day average of 426.74K.
- Price is +0.2% vs its 50-day average ($32.92) and +13.8% vs its 200-day average ($29.01).
- 52-week range $17.72–$44.28; today's close sits at 58% of that range, 25.5% below the 52-week high.
Oct 6, 2026 — CSTL slides 9.0% to $33.36
- Closed at $33.36, -8.98% vs the prior close of $36.65. Day range $33.10–$37.99, opened at $36.65.
- Volume was 609.10K shares, 1.4x its 50-day average of 420.39K.
- Price is +1.9% vs its 50-day average ($32.74) and +14.9% vs its 200-day average ($29.04).
- 52-week range $17.72–$44.28; today's close sits at 59% of that range, 24.7% below the 52-week high.
Oct 5, 2026 — CSTL jumps 3.1% to $36.65
- Closed at $36.65, +3.07% vs the prior close of $35.56. Day range $35.10–$36.76, opened at $35.45.
- Volume was 377.20K shares, 0.9x its 50-day average of 421.02K.
- Price is +12.5% vs its 50-day average ($32.56) and +26.1% vs its 200-day average ($29.07).
- 52-week range $17.72–$44.28; today's close sits at 71% of that range, 17.2% below the 52-week high.
Oct 2, 2026 — CSTL rises 0.9% to $35.56
- Closed at $35.56, +0.87% vs the prior close of $35.26. Day range $34.75–$35.92, opened at $35.56.
- Volume was 167.70K shares, 0.4x its 50-day average of 425.83K — lighter than usual.
- Price is +10.0% vs its 50-day average ($32.33) and +22.3% vs its 200-day average ($29.09).
- 52-week range $17.72–$44.28; today's close sits at 67% of that range, 19.7% below the 52-week high.
CSTL latest news & SEC filings
Every SEC filing by or about CSTL in the last 120 days, explained in plain English. Updated daily, with a same-day refresh for new filings.
Oct 14, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Juvenal Tobin W sold 3,288 shares at $33.64 (≈$110.61K) on Oct 12, 2026; now holds 48,719
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Oct 13, 2026 · Form 144 — Planned insider sale
Notice of proposed sale (Form 144) — an insider or affiliate plans to sell restricted or control shares
A notice of intent, not a completed sale. Any actual sale by a director or officer shows up later on Form 4.
Oct 7, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Maetzold Derek J converted options/RSUs into 8,165 shares at $2.39 (≈$19.51K) on Oct 5, 2026; now holds 29,644
- Maetzold Derek J sold 8,580 shares at $35.57 (≈$305.16K) on Oct 5, 2026; now holds 21,064
- Maetzold Derek J sold 3,198 shares at $35.57 (≈$113.74K) on Oct 5, 2026; now holds 8,038
- Maetzold Derek J sold 2,718 shares at $35.57 (≈$96.67K) on Oct 5, 2026; now holds 6,832
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Oct 5, 2026 · Form 144 — Planned insider sale
Notice of proposed sale (Form 144) — an insider or affiliate plans to sell restricted or control shares
A notice of intent, not a completed sale. Any actual sale by a director or officer shows up later on Form 4.
Oct 5, 2026 · Form 4 — Insider trade
Insider trade report (Form 4) — a director, officer or 10%+ owner changed their holdings
- Oelschlager Kristen M converted options/RSUs into 4,153 shares at $3.38 (≈$14.04K) on Oct 1, 2026; now holds 17,509
- Oelschlager Kristen M sold 2,807 shares at $35.75 (≈$100.35K) on Oct 1, 2026; now holds 14,702
- Oelschlager Kristen M sold 1,346 shares at $36.38 (≈$48.97K) on Oct 1, 2026; now holds 13,356
Open-market purchases (P) and sales (S) are shown in colour; awards, exercises and tax withholding are routine pay-related moves. Many sales are pre-planned under 10b5-1 plans.
Oct 1, 2026 · Form 144 — Planned insider sale
Notice of proposed sale (Form 144) — an insider or affiliate plans to sell restricted or control shares
A notice of intent, not a completed sale. Any actual sale by a director or officer shows up later on Form 4.
Aug 14, 2026 · Form 8-A12B — 8-A12B filing
8-A12B filing
Jul 30, 2026 · Form 10-Q — Quarterly report
Quarterly report (unaudited financial statements for the quarter)
Quarter ended Jun 30, 2026:
- Revenue: $103.55M (prior year $86.19M) (+20.1% vs Jun 30, 2025)
- Net income: -$2.06M (prior year $4.52M) (loss widened vs Jun 30, 2025)
- Diluted EPS: -$0.07 (prior year $0.15) (loss widened vs Jun 30, 2025)
Jul 30, 2026 · Form 8-K — Major event / current report
Current report — a filing companies must make within 4 business days of a major event
- Item 2.02 — Reported results of operations (earnings release).
- Item 7.01 — Released information under Regulation FD (e.g. a presentation or press release).
This is a results-day filing: the earnings press release is attached as an exhibit.
Things to know before you trade CSTL
- Last results release: Jul 30, 2026 (8-K Item 2.02). Previous ones: May 6, 2026, Feb 26, 2026, Jan 13, 2026. Based on that rhythm, the next report is likely around Oct 29, 2026 — an estimate, not a confirmed date.
- How much it moves: over the last 20 sessions the average daily move was 2.01% (largest 9.0%).
- Liquidity: about 376.06K shares (≈$12.71M) trade per day on average.
- 52-week position: $33.80 vs a range of $17.72–$44.28 (61% of the range).
- Dividends: no cash dividends in the last 2 years.
- Splits: none in the last 2 years.
- Insider trades (Form 4, last 12 months, recent 25 shown): 0 open-market buys, 25 sales; latest: Derek J Maetzold sold 2,718 shares on Sep 21, 2026.
- Latest filings: 10-Q Jul 30, 2026; 8-K Jul 30, 2026; 8-K May 29, 2026.
- Share count: 30.55M shares outstanding (Jul 23, 2026), +5.3% vs a year earlier — notable dilution.
- Listing: Nasdaq · industry: Services-Medical Laboratories.
CSTL market data (last 20 sessions)
| Date | Open | High | Low | Close | Volume |
|---|---|---|---|---|---|
| Oct 15, 2026 | 33.13 | 34.06 | 32.48 | 33.80 | 381.90K |
| Oct 14, 2026 | 32.47 | 33.77 | 32.47 | 33.11 | 243.20K |
| Oct 13, 2026 | 32.79 | 33.35 | 32.23 | 32.88 | 241.70K |
| Oct 12, 2026 | 34.42 | 34.42 | 32.31 | 32.76 | 239.00K |
| Oct 9, 2026 | 33.52 | 34.52 | 33.39 | 34.42 | 249.10K |
| Oct 8, 2026 | 32.54 | 33.76 | 32.25 | 33.71 | 373.80K |
| Oct 7, 2026 | 33.15 | 33.72 | 32.77 | 33.00 | 351.50K |
| Oct 6, 2026 | 36.65 | 37.99 | 33.10 | 33.36 | 609.10K |
| Oct 5, 2026 | 35.45 | 36.76 | 35.10 | 36.65 | 377.20K |
| Oct 2, 2026 | 35.56 | 35.92 | 34.75 | 35.56 | 167.70K |
| Oct 1, 2026 | 36.10 | 36.99 | 35.17 | 35.26 | 522.30K |
| Sep 30, 2026 | 34.90 | 36.03 | 34.14 | 35.53 | 639.60K |
| Sep 29, 2026 | 35.72 | 36.24 | 34.24 | 34.88 | 318.60K |
| Sep 28, 2026 | 35.81 | 36.26 | 35.08 | 35.93 | 228.40K |
| Sep 25, 2026 | 35.19 | 36.12 | 34.44 | 35.81 | 437.70K |
| Sep 24, 2026 | 34.88 | 35.84 | 33.90 | 35.19 | 439.20K |
| Sep 23, 2026 | 34.74 | 34.97 | 33.99 | 34.88 | 348.30K |
| Sep 22, 2026 | 35.53 | 35.53 | 34.57 | 34.85 | 431.00K |
| Sep 21, 2026 | 35.68 | 35.68 | 34.48 | 34.99 | 391.70K |
| Sep 18, 2026 | 36.54 | 36.54 | 35.29 | 35.34 | 530.20K |
About Castle Biosciences
Castle Biosciences (CSTL) is listed on the Nasdaq and classified by the SEC under “Services-Medical Laboratories”. Its business address is in FRIENDSWOOD, TX. State of incorporation: DE. Fiscal year ends December 31. SEC CIK 1447362.
CSTL board of directors & executives
From SEC Form 3/4/5 insider filings made in the last 12 months (date = latest filing).
Directors
| Name | Role | Latest filing |
|---|---|---|
| Daniel Bradbury | Director | Jun 1, 2026 |
| Kim Caple | Director | Jun 1, 2026 |
| G Bradley Cole | Director | Jun 1, 2026 |
| Rodney Cotton | Director | Jun 1, 2026 |
| Ellen Goldberg | Director | Jun 1, 2026 |
| Miles Harrison | Director | Jun 1, 2026 |
| Derek J Maetzold | Pres. & Chief Exec. Officer | Sep 23, 2026 |
| Tiffany Olson | Director | Jun 1, 2026 |
Executive officers
| Name | Title | Latest filing |
|---|---|---|
| Tobin W Juvenal | Chief Commercial Officer | Sep 16, 2026 |
| Derek J Maetzold | Pres. & Chief Exec. Officer | Sep 23, 2026 |
| Kristen M Oelschlager | Chief Operating Officer | Sep 3, 2026 |
| Frank Stokes | Chief Financial Officer | Aug 18, 2026 |
Recent insider buys & sales
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Sep 21, 2026 | Derek J Maetzold | Sale | 2,718 | $35.33 |
| Sep 21, 2026 | Derek J Maetzold | Sale | 3,198 | $35.33 |
| Sep 21, 2026 | Derek J Maetzold | Sale | 8,580 | $35.33 |
| Sep 15, 2026 | Tobin W Juvenal | Sale | 3,294 | $35.14 |
| Sep 14, 2026 | Tobin W Juvenal | Sale | 3,306 | $32.32 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 8,361 | $32.00 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 3,124 | $32.00 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 2,656 | $32.00 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 71 | $32.78 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 83 | $32.78 |
| Sep 11, 2026 | Derek J Maetzold | Sale | 223 | $32.78 |
| Sep 1, 2026 | Kristen M Oelschlager | Sale | 200 | $34.02 |
| Sep 1, 2026 | Kristen M Oelschlager | Sale | 3,952 | $33.36 |
| Aug 31, 2026 | Tobin W Juvenal | Sale | 1,730 | $32.81 |
| Aug 28, 2026 | Derek J Maetzold | Sale | 2,505 | $33.14 |
CSTL financials (annual, from XBRL filings)
| Fiscal year end | Revenue | Net income | Diluted EPS | Operating cash flow |
|---|---|---|---|---|
| Dec 31, 2025 | $344.23M | $-24.16M | -0.83 | $64.35M |
| Dec 31, 2024 | $332.07M | $18.25M | 0.62 | $64.87M |
| Dec 31, 2023 | $219.79M | $-57.47M | -2.14 | $-5.63M |
| Dec 31, 2022 | $137.04M | $-67.14M | -2.58 | $-41.66M |
| Dec 31, 2021 | $94.08M | $-31.29M | -1.24 | $-18.98M |
Latest balance sheet: total assets $561.18M, total liabilities $91.15M, cash $62.12M (as of Jun 30, 2026).
CSTL earnings / results-day log
| Date | Filing | Close that day |
|---|---|---|
| Jul 30, 2026 | 8-K Item 2.02 (results) | $26.79 |
| May 6, 2026 | 8-K Item 2.02 (results) | $24.75 |
| Feb 26, 2026 | 8-K Item 2.02 (results) | $31.88 |
| Jan 13, 2026 | 8-K Item 2.02 (results) | $39.64 |
| Nov 3, 2025 | 8-K Item 2.02 (results) | $25.99 |
| Aug 4, 2025 | 8-K Item 2.02 (results) | $15.32 |
| May 5, 2025 | 8-K Item 2.02 (results) | $18.75 |
| Feb 27, 2025 | 8-K Item 2.02 (results) | $25.28 |
| Jan 13, 2025 | 8-K Item 2.02 (results) | $26.15 |
| Nov 4, 2024 | 8-K Item 2.02 (results) | $33.64 |
| Aug 5, 2024 | 8-K Item 2.02 (results) | — |
| May 2, 2024 | 8-K Item 2.02 (results) | — |
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Information only, not investment advice. BuyMeWhiskey is not a registered investment adviser or broker-dealer; nothing here is a recommendation to buy, sell or hold any security, and there are no price targets. Data comes from SEC EDGAR filings and public end-of-day market data and may be delayed or contain errors. Verify with the company's filings before making decisions. Prices: end-of-day data as of Oct 15, 2026, 4:00 PM ET. Filings: SEC EDGAR. Updated after every US trading day.