CASTLE BIOSCIENCES INC (CSTL) Institutional Ownership Changes & 13F Activity
CASTLE BIOSCIENCES INC (CSTL). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q2 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include Portolan Capital Management, Llc, Jefferies Financial Group Inc., Point72 Asset Management, L.P., Kennedy Capital Management Llc, and Palisade Capital Management, Lp.
| Institution | Type | Change in shares | Change Position % | Shares | Reported stock balance | Portfolio quarter | Filing date |
|---|---|---|---|---|---|---|---|
| Envestnet Asset Management Inc | Sell | -6,708 | -10.8% | 55,157 | $1.32M | Q2 2026 | Sep 23, 2026 |
| State Street Corp | Buy | +53,000 | +6.9% | 822,079 | $19.63M | Q2 2026 | Sep 22, 2026 |
| Manufacturers Life Insurance Company, The | Buy | +105 | +0.8% | 12,543 | $299.15K | Q2 2026 | Sep 09, 2026 |
| Citadel Advisors Llc | Buy | +144,376 | +119.3% | 265,353 | $6.33M | Q2 2026 | Sep 02, 2026 |
| Allianz Asset Management Gmbh | Buy | +67,934 | +8.4% | 879,258 | $20.97M | Q2 2026 | Sep 02, 2026 |
| California State Teachers Retirement System | Buy | +10,289 | +37.4% | 37,802 | $901.58K | Q2 2026 | Aug 24, 2026 |
| Jefferies Financial Group Inc. | Buy | +647,391 | — | 647,391 | $15.44M | Q2 2026 | Aug 17, 2026 |
| Empowered Funds, Llc | Buy | +10,154 | +7.7% | 142,338 | $3.39M | Q2 2026 | Aug 17, 2026 |
| Portolan Capital Management, Llc | Sell | -1,021,465 | -75.6% | 328,818 | $7.84M | Q2 2026 | Aug 14, 2026 |
| Point72 Asset Management, L.P. | Buy | +357,317 | — | 357,317 | $8.52M | Q2 2026 | Aug 14, 2026 |
| Kennedy Capital Management Llc | Buy | +348,371 | — | 348,371 | $8.31M | Q2 2026 | Aug 14, 2026 |
| Palisade Capital Management, Lp | Sell | -303,953 | -56.7% | 231,931 | $5.53M | Q2 2026 | Aug 14, 2026 |
| Tudor Investment Corp Et Al | Sell | -208,520 | -93.5% | 14,462 | $344.92K | Q2 2026 | Aug 14, 2026 |
| Two Sigma Investments, Lp | Sell | -148,466 | -59.7% | 100,374 | $2.39M | Q2 2026 | Aug 14, 2026 |
| Millennium Management Llc | Sell | -147,950 | -41.9% | 205,369 | $4.90M | Q2 2026 | Aug 14, 2026 |
| Summit Partners Public Asset Management, Llc | Sell | -115,813 | -12.3% | 824,872 | $19.67M | Q2 2026 | Aug 14, 2026 |
| Aqr Capital Management Llc | Buy | +101,687 | +156.7% | 166,567 | $3.97M | Q2 2026 | Aug 14, 2026 |
| Hrt Financial Lp | Buy | +99,995 | +630.6% | 115,853 | $2.76M | Q2 2026 | Aug 14, 2026 |
| D. E. Shaw & Co., Inc. | Sell | -99,177 | -46.8% | 112,789 | $2.69M | Q2 2026 | Aug 14, 2026 |
| Trexquant Investment Lp | Buy | +75,677 | +58.0% | 206,111 | $4.92M | Q2 2026 | Aug 14, 2026 |
| Man Group Plc | Buy | +61,623 | +130.7% | 108,761 | $2.59M | Q2 2026 | Aug 14, 2026 |
| Invesco Ltd. | Buy | +54,888 | — | 54,888 | $1.31M | Q2 2026 | Aug 14, 2026 |
| Sei Investments Co | Buy | +39,387 | +112.4% | 74,433 | $1.78M | Q2 2026 | Aug 14, 2026 |
| Bridgeway Capital Management, Llc | Sell | -33,846 | -13.3% | 221,338 | $5.28M | Q2 2026 | Aug 14, 2026 |
| Bank Of America Corp | Buy | +30,935 | +45.6% | 98,745 | $2.36M | Q2 2026 | Aug 14, 2026 |
| Qube Research & Technologies Ltd | Buy | +29,717 | +5.3% | 589,300 | $14.05M | Q2 2026 | Aug 14, 2026 |
| Schonfeld Strategic Advisors Llc | Sell | -22,483 | -53.0% | 19,930 | $475.33K | Q2 2026 | Aug 14, 2026 |
| Rtw Investments, Lp | Buy | +20,000 | +0.7% | 2,778,335 | $66.26M | Q2 2026 | Aug 14, 2026 |
| Xtx Topco Ltd | Buy | +19,640 | +96.8% | 39,923 | $952.16K | Q2 2026 | Aug 14, 2026 |
| Parkman Healthcare Partners Llc | Buy | +18,641 | +14.8% | 144,791 | $3.45M | Q2 2026 | Aug 14, 2026 |
Frequently asked questions about CSTL activity
Which institutional owners are buying CSTL?
Institutional owners buying CSTL include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in CSTL activity?
"Buy" means an investor increased their reported position in CSTL compared to the prior reporting period. This reflects growing exposure to CASTLE BIOSCIENCES INC (CSTL) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in CSTL increasing?
Institutional interest in CSTL can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.
Related CSTL Institutional Insights
- CSTL Overview
- CSTL 13F Institutional Holders
- CSTL Top Institutional Shareholders
- Healthcare Sector Institutional Ownership
- Healthcare Sector Portfolio Overlap
- Institutional Portfolio Overlap & Shared Holdings
- Most Bought Healthcare Stocks By Institutional Investors
- Most Sold Healthcare Stocks By Institutional Investors
- CSTL Insider Trading & SEC Form 4 Activity
- CSTL Articles
- Top Institutional Investor Stock Rankings