CSTL
CASTLE BIOSCI (CSTL)
NASDAQ
$32.35+$0.02 (+0.05%)
Price as of Sep 11, 2026 7:30 PM EDT
  • $987.7M
    Market Cap
  • 50.93%
    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

  • Institutions472.3M (75.74%)
  • Mutual Funds147.3M (23.62%)
  • Insiders4.0M (0.63%)
  • Other0 (0.00%)

Insider Transactions

  • 0.63% (4.0M)
    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)
  • $89.1M
    Amount of InsiderSelling (last 12 months)
Insider Name & Title
Type
Date
Transaction Value
Shares
Share Price
Shares After Transactions
Oelschlager Kristen M
Chief Operating Officer
Exempt
Sep 01, 2026
$0.00
4,152
$0.00
12,458
Oelschlager Kristen M
Chief Operating Officer
Exempt
Sep 01, 2026
$14,033.76
4,152
$3.38
17,508
Oelschlager Kristen M
Chief Operating Officer
Sell
Sep 01, 2026
$131,838.72
3,952
$33.36
13,556
Oelschlager Kristen M
Chief Operating Officer
Sell
Sep 01, 2026
$6,804.00
200
$34.02
13,356
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Aug 28, 2026
$0.00
12,428
$0.00
25,329
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Aug 28, 2026
$29,702.92
12,428
$2.39
33,907
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$380,182.08
11,472
$33.14
22,435
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$83,015.70
2,505
$33.14
17,850
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$70,555.06
2,129
$33.14
15,172
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$8,516.98
257
$33.14
11,277
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$8,516.98
257
$33.14
11,277
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$8,516.98
257
$33.14
11,277
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$8,516.98
257
$33.14
11,277
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$32,389.28
956
$33.88
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$7,080.92
209
$33.88
17,641
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$5,996.76
177
$33.88
14,995
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$711.48
21
$33.88
11,256
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$711.48
21
$33.88
11,256
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$711.48
21
$33.88
11,256
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 28, 2026
$711.48
21
$33.88
11,256
Oelschlager Kristen M
Chief Operating Officer
Sell
Aug 25, 2026
$245,357.34
7,161
$34.26
77,872
Oelschlager Kristen M
Chief Operating Officer
Sell
Aug 25, 2026
$180,919.50
5,223
$34.64
72,649
Oelschlager Kristen M
Chief Operating Officer
Sell
Aug 24, 2026
$411,587.77
12,218
$33.69
85,033
Juvenal Tobin W
Chief Commercial Officer
Sell
Aug 17, 2026
$51,190.70
1,730
$29.59
75,964
Stokes Frank
Chief Financial Officer
Sell
Aug 14, 2026
$741,511.16
24,908
$29.77
35,177
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Aug 14, 2026
$0.00
1,100
$0.00
37,757
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Aug 14, 2026
$2,629.00
1,100
$2.39
22,579
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 14, 2026
$33,022.00
1,100
$30.02
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 14, 2026
$81,474.28
2,714
$30.02
20,355
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Aug 14, 2026
$69,226.12
2,306
$30.02
17,301