CSTL
CASTLE BIOSCI (CSTL)
NASDAQ
$33.70-$0.29 (-0.86%)
Price as of Nov 12, 2026 9:35 AM EST
  • $1.0B
    Market Cap
  • -2.38%
    1-Year Change
  • Diagnostics & Research
    Industry

Top Holders

Institutional
Mutual Funds
Holder
Ownership %
Shares Held
Change (Shares, %)
Report Date
BLACKROCK, INC.
10.68%
3.3M
+309,017 (+9.39%)
Jun 30, 2026
WASATCH ADVISORS INC
10.46%
3.2M
-122,185 (-3.79%)
Dec 31, 2022
BLACKROCK INC.
9.88%
3.0M
+449,286 (+14.76%)
Jun 30, 2024
BLACKROCK FUNDING, INC. /DE
9.48%
2.9M
-198,963 (-6.81%)
Dec 31, 2024
RTW INVESTMENTS, LP
9.02%
2.8M
+20,000 (+0.72%)
Jun 30, 2026
VANGUARD GROUP INC
7.14%
2.2M
+27,511 (+1.25%)
Dec 31, 2025
PRINCIPAL FINANCIAL GROUP INC
4.87%
1.5M
-225,751 (-15.04%)
Sep 30, 2026

Current Ownership Distribution

  • Institutions479.9M (75.09%)
  • Mutual Funds155.3M (24.30%)
  • Insiders3.9M (0.61%)
  • Other0 (0.00%)

Insider Transactions

  • 0.61% (3.9M)
    Current InsiderOwnership (%, shares)
  • 0
    Number of InsiderBuying (last 12 months)
  • $0.00
    Amount of InsiderBuying (last 12 months)
  • 4
    Number of InsiderSelling (last 12 months)
  • $93.9M
    Amount of InsiderSelling (last 12 months)
Insider Name & Title
Type
Date
Transaction Value
Shares
Share Price
Shares After Transactions
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$272,017.78
7,555
$36.01
4,929
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$101,390.08
2,816
$36.01
2,024
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$86,159.96
2,393
$36.01
1,721
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$37,734.35
1,025
$36.81
3,904
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$14,062.95
382
$36.81
1,642
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Nov 02, 2026
$11,964.55
325
$36.81
1,396
Juvenal Tobin W
Chief Commercial Officer
Sell
Oct 28, 2026
$44,008.75
1,237
$35.58
44,194
Juvenal Tobin W
Chief Commercial Officer
Sell
Oct 28, 2026
$195,582.08
5,341
$36.62
38,853
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 19, 2026
$273,787.80
8,580
$31.91
12,484
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 19, 2026
$102,048.18
3,198
$31.91
4,840
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 19, 2026
$86,731.38
2,718
$31.91
4,114
Juvenal Tobin W
Chief Commercial Officer
Sell
Oct 12, 2026
$110,608.32
3,288
$33.64
48,719
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Oct 05, 2026
$0.00
8,165
$0.00
0
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Oct 05, 2026
$19,514.35
8,165
$2.39
29,644
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 05, 2026
$305,156.28
8,580
$35.57
21,064
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 05, 2026
$113,740.07
3,198
$35.57
8,038
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Oct 05, 2026
$96,668.39
2,718
$35.57
6,832
Oelschlager Kristen M
Chief Operating Officer
Exempt
Oct 01, 2026
$0.00
4,153
$0.00
8,305
Oelschlager Kristen M
Chief Operating Officer
Exempt
Oct 01, 2026
$14,037.14
4,153
$3.38
17,509
Oelschlager Kristen M
Chief Operating Officer
Sell
Oct 01, 2026
$100,350.25
2,807
$35.75
14,702
Oelschlager Kristen M
Chief Operating Officer
Sell
Oct 01, 2026
$48,967.48
1,346
$36.38
13,356
Juvenal Tobin W
Chief Commercial Officer
Sell
Sep 30, 2026
$35,362.80
1,034
$34.20
52,007
Juvenal Tobin W
Chief Commercial Officer
Sell
Sep 29, 2026
$196,765.41
5,543
$35.50
53,041
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Sep 21, 2026
$0.00
8,580
$0.00
8,165
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Sep 21, 2026
$20,506.20
8,580
$2.39
30,059
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 21, 2026
$303,165.72
8,580
$35.33
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 21, 2026
$112,998.13
3,198
$35.33
11,236
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 21, 2026
$96,037.81
2,718
$35.33
9,550
Juvenal Tobin W
Chief Commercial Officer
Sell
Sep 15, 2026
$115,757.75
3,294
$35.14
58,584
Juvenal Tobin W
Chief Commercial Officer
Sell
Sep 14, 2026
$106,863.14
3,306
$32.32
61,878