CSTL
CASTLE BIOSCI (CSTL)
NASDAQ
$33.18-$0.010 (-0.03%)
Price as of Oct 22, 2026 7:30 PM EDT
  • $1.0B
    Market Cap
  • 37.26%
    1-Year Change
  • Diagnostics & Research
    Industry

Top Holders

Institutional
Mutual Funds
Holder
Ownership %
Shares Held
Change (Shares, %)
Report Date
BLACKROCK, INC.
10.78%
3.3M
+309,017 (+9.39%)
Jun 30, 2026
WASATCH ADVISORS INC
10.55%
3.2M
-122,185 (-3.79%)
Dec 31, 2022
BLACKROCK INC.
9.97%
3.0M
+449,286 (+14.76%)
Jun 30, 2024
BLACKROCK FUNDING, INC. /DE
9.56%
2.9M
-198,963 (-6.81%)
Dec 31, 2024
RTW INVESTMENTS, LP
9.09%
2.8M
+20,000 (+0.72%)
Jun 30, 2026
VANGUARD GROUP INC
7.20%
2.2M
+27,511 (+1.25%)
Dec 31, 2025
PRINCIPAL FINANCIAL GROUP INC
5.65%
1.7M
-43,229 (-2.50%)
Jun 30, 2026

Current Ownership Distribution

  • Institutions472.7M (75.07%)
  • Mutual Funds153.0M (24.30%)
  • Insiders3.9M (0.63%)
  • Other0 (0.00%)

Insider Transactions

  • 0.63% (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)
  • $100.5M
    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
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
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Sep 11, 2026
$0.00
8,584
$0.00
16,745
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Sep 11, 2026
$20,515.76
8,584
$2.39
30,063
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$267,552.00
8,361
$32.00
21,702
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$99,968.00
3,124
$32.00
14,517
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$84,992.00
2,656
$32.00
12,339
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$7,309.94
223
$32.78
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$2,720.74
83
$32.78
14,434
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Sep 11, 2026
$2,327.38
71
$32.78
12,268