CSTL
CASTLE BIOSCI (CSTL)
NASDAQ
$22.11+$0.73 (+3.43%)
Price as of Jun 23, 2026 7:10 PM EDT
  • $643.0M
    Market Cap
  • 12.47%
    1-Year Change
  • Diagnostics & Research
    Industry

Top Holders

Institutional
Mutual Funds
Holder
Ownership %
Shares Held
Change (Shares, %)
Report Date
WASATCH ADVISORS INC
10.63%
3.2M
-122,185 (-3.79%)
Dec 31, 2022
BLACKROCK INC.
10.04%
3.0M
+449,286 (+14.76%)
Jun 30, 2024
BLACKROCK, INC.
9.83%
3.0M
-122,300 (-4.10%)
Mar 31, 2026
BLACKROCK FUNDING, INC. /DE
9.63%
2.9M
-198,963 (-6.81%)
Dec 31, 2024
RTW INVESTMENTS, LP
9.09%
2.8M
+643,098 (+23.31%)
Mar 31, 2026
VANGUARD GROUP INC
7.25%
2.2M
+27,511 (+1.25%)
Dec 31, 2025
PRINCIPAL FINANCIAL GROUP INC
5.84%
1.8M
-37,767 (-2.13%)
Mar 31, 2026

Current Ownership Distribution

  • Institutions443.8M (76.42%)
  • Mutual Funds133.0M (22.90%)
  • Insiders3.9M (0.67%)
  • Other0 (0.00%)

Insider Transactions

  • 0.67% (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)
  • $70.5M
    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
Exempt
Apr 06, 2026
$0.00
6,214
$0.00
7,518
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Apr 06, 2026
$14,851.46
6,214
$2.39
27,693
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$155,536.42
6,214
$25.03
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$33,965.71
1,357
$25.03
48,852
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$28,859.59
1,153
$25.03
41,520
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$6,958.34
278
$25.03
2,780
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$6,958.34
278
$25.03
2,780
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$6,958.34
278
$25.03
2,780
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Apr 06, 2026
$6,958.34
278
$25.03
2,780
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Mar 26, 2026
$0.00
550
$0.00
13,732
Cotton Rodney
Exempt
Mar 26, 2026
$0.00
5,329
$0.00
5,330
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Mar 26, 2026
$1,314.50
550
$2.39
22,029
Cotton Rodney
Exempt
Mar 26, 2026
$0.00
5,329
$0.00
19,331
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$14,053.05
550
$25.55
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$34,672.71
1,357
$25.55
50,209
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$29,460.30
1,153
$25.55
42,673
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$7,103.18
278
$25.55
3,058
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$7,103.18
278
$25.55
3,058
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$7,103.18
278
$25.55
3,058
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 26, 2026
$7,103.18
278
$25.55
3,058
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 18, 2026
$16,503.50
650
$25.39
21,479
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 17, 2026
$483,594.50
18,650
$25.93
22,129
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 16, 2026
$453,045.84
17,449
$25.96
40,905
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 16, 2026
$3,361.68
126
$26.68
40,779
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 13, 2026
$336,002.19
13,204
$25.45
58,354
Juvenal Tobin W
Chief Commercial Officer
Sell
Mar 12, 2026
$526,582.12
20,863
$25.24
86,825
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 12, 2026
$585,941.94
23,179
$25.28
71,558
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Mar 11, 2026
$0.00
6,226
$0.00
14,282
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Exempt
Mar 11, 2026
$14,880.14
6,226
$2.39
112,047
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
Sell
Mar 11, 2026
$451,946.79
17,310
$26.11
94,737