CASTLE BIOSCIENCES INC (CSTL) Institutional Shareholders
CASTLE BIOSCIENCES INC (CSTL) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $627.85M in CSTL holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of CSTL tracked by InsiderSet, reporting ownership valued at approximately $78.51M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $98.59M, representing an estimated gain of +25.58% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 53% of the total disclosed CSTL value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Rtw Investments, Lp, Principal Financial Group Inc, and several other long-term asset managers with concentrated positions in CASTLE BIOSCIENCES INC (CSTL).
This page ranks the largest institutional CSTL shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
175
Total Reported Value
$627.85M
Largest Holder
Blackrock, Inc.
Largest Position
$78.51M
Insider Transactions (90d)
50
Latest Filing Quarter
Q2 2026
New Institutional Positions
49
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.00% | 3,291,963 | $78,513,319 | $98,594,292 | +$20,080,973 | +25.58% | |
| Rtw Investments, Lp | 0.57% | 2,778,335 | $66,263,290 | $83,211,133 | +$16,947,843 | +25.58% | |
| Principal Financial Group Inc | 0.02% | 1,726,648 | $41,180,555 | $51,713,108 | +$10,532,553 | +25.58% | |
| Vanguard Capital Management Llc | 0.00% | 1,226,497 | $29,251,953 | $36,733,585 | +$7,481,632 | +25.58% | |
| Vanguard Portfolio Management Llc | 0.00% | 840,785 | $20,052,722 | $25,181,511 | +$5,128,789 | +25.58% | |
| Allianz Asset Management Gmbh | 0.02% | 811,324 | $19,918,004 | $24,299,154 | +$4,381,150 | +22.00% | |
| Summit Partners Public Asset Management, Llc | 0.51% | 824,872 | $19,673,197 | $24,704,916 | +$5,031,719 | +25.58% | |
| State Street Corp | 0.00% | 822,079 | $19,630,772 | $24,621,266 | +$4,990,494 | +25.42% | |
| Geode Capital Management, Llc | 0.00% | 795,912 | $18,986,390 | $23,837,564 | +$4,851,174 | +25.55% | |
| Mackenzie Financial Corp | 0.02% | 793,507 | $18,925,142 | $23,765,535 | +$4,840,393 | +25.58% | |
| Dimensional Fund Advisors Lp | 0.00% | 791,085 | $18,868,635 | $23,692,996 | +$4,824,361 | +25.57% | |
| Jefferies Financial Group Inc. | 0.14% | 647,391 | $15,440,275 | $19,389,360 | +$3,949,085 | +25.58% | |
| Qube Research & Technologies Ltd | 0.02% | 589,300 | $14,054,805 | $17,649,535 | +$3,594,730 | +25.58% | |
| Aigh Capital Management Llc | 1.18% | 545,101 | $13,000,659 | $16,325,775 | +$3,325,116 | +25.58% | |
| Renaissance Technologies LLC | Jim Simons | 0.01% | 371,200 | $8,853,120 | $11,117,440 | +$2,264,320 | +25.58% |
| Goldman Sachs Group Inc | 0.00% | 358,397 | $8,547,768 | $10,733,990 | +$2,186,222 | +25.58% | |
| Point72 Asset Management, L.P. | 0.01% | 357,317 | $8,522,010 | $10,701,644 | +$2,179,634 | +25.58% | |
| Kennedy Capital Management Llc | 0.15% | 348,371 | $8,308,648 | $10,433,711 | +$2,125,063 | +25.58% | |
| Connor, Clark & Lunn Investment Management Ltd. | 0.01% | 331,727 | $7,911,689 | $9,935,224 | +$2,023,535 | +25.58% | |
| Morgan Stanley | 0.00% | 329,684 | $7,862,987 | $9,874,036 | +$2,011,049 | +25.58% | |
| Portolan Capital Management, Llc | 0.29% | 328,818 | $7,842,309 | $9,848,099 | +$2,005,790 | +25.58% | |
| Panagora Asset Management Inc | 0.02% | 301,040 | $7,179,804 | $9,016,148 | +$1,836,344 | +25.58% | |
| Allspring Global Investments Holdings, Llc | 0.01% | 292,470 | $6,975,410 | $8,759,477 | +$1,784,067 | +25.58% | |
| Northern Trust Corp | 0.00% | 285,158 | $6,801,019 | $8,540,482 | +$1,739,463 | +25.58% | |
| Wasatch Advisors Lp | 0.04% | 279,349 | $6,662,474 | $8,366,503 | +$1,704,029 | +25.58% | |
| Citadel Advisors Llc | 0.00% | 265,353 | $6,328,669 | $7,947,322 | +$1,618,653 | +25.58% | |
| Kornitzer Capital Management Inc | 0.13% | 264,235 | $6,302,005 | $7,913,838 | +$1,611,833 | +25.58% | |
| Silvercrest Asset Management Group Llc | 0.04% | 256,095 | $6,107,866 | $7,670,045 | +$1,562,179 | +25.58% | |
| Charles Schwab Investment Management Inc | 0.00% | 254,535 | $6,070,660 | $7,623,323 | +$1,552,663 | +25.58% | |
| Sixth Street Partners Management Company, L.P. | 0.00% | 254,535 | $6,070,660 | $7,623,323 | +$1,552,663 | +25.58% | |
| Advisors Capital Management, Llc | 0.06% | 238,204 | $5,681,165 | $7,134,210 | +$1,453,045 | +25.58% | |
| New York State Common Retirement Fund | 0.01% | 234,746 | $5,598,692 | $7,030,643 | +$1,431,951 | +25.58% | |
| Palisade Capital Management, Lp | 0.24% | 231,931 | $5,531,554 | $6,946,333 | +$1,414,779 | +25.58% | |
| Nuveen, Llc | 0.00% | 231,726 | $5,526,666 | $6,940,194 | +$1,413,528 | +25.58% | |
| Bridgeway Capital Management, Llc | 0.09% | 221,338 | $5,278,911 | $6,629,073 | +$1,350,162 | +25.58% | |
| Trexquant Investment Lp | 0.03% | 206,111 | $4,915,747 | $6,173,024 | +$1,257,277 | +25.58% | |
| Millennium Management Llc | 0.00% | 205,369 | $4,898,051 | $6,150,802 | +$1,252,751 | +25.58% | |
| Vanguard Fiduciary Trust Co | 0.00% | 197,494 | $4,710,232 | $5,914,945 | +$1,204,713 | +25.58% | |
| Aqr Capital Management Llc | 0.00% | 166,567 | $3,972,623 | $4,988,682 | +$1,016,059 | +25.58% | |
| First Trust Advisors Lp | 0.00% | 145,064 | $3,459,776 | $4,344,667 | +$884,891 | +25.58% | |
| Parkman Healthcare Partners Llc | 0.35% | 144,791 | $3,453,265 | $4,336,490 | +$883,225 | +25.58% | |
| Empowered Funds, Llc | 0.02% | 142,338 | $3,394,761 | $4,263,023 | +$868,262 | +25.58% | |
| D. E. Shaw & Co., Inc. | 0.00% | 112,789 | $2,690,018 | $3,378,031 | +$688,013 | +25.58% | |
| Man Group Plc | 0.00% | 108,761 | $2,593,950 | $3,257,392 | +$663,442 | +25.58% | |
| Two Sigma Investments, Lp | 0.00% | 100,374 | $2,393,920 | $3,006,201 | +$612,281 | +25.58% | |
| Bank Of America Corp | 0.00% | 98,745 | $2,355,069 | $2,957,413 | +$602,344 | +25.58% | |
| Bank Of New York Mellon Corp | 0.00% | 98,018 | $2,337,724 | $2,935,639 | +$597,915 | +25.58% | |
| Arrowstreet Capital, Limited Partnership | 0.00% | 92,736 | $2,211,754 | $2,777,443 | +$565,689 | +25.58% | |
| Ubs Group Ag | 0.00% | 89,368 | $2,131,427 | $2,676,572 | +$545,145 | +25.58% | |
| Jpmorgan Chase & Co | 0.00% | 84,804 | $2,062,434 | $2,539,880 | +$477,446 | +23.15% |
Frequently asked questions about CSTL
Who owns the most CSTL stock?
The largest holders of CSTL are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for CASTLE BIOSCIENCES INC (CSTL).
Is CSTL widely held by superinvestors?
Many widely followed stocks like CSTL appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly CSTL is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.