Castle Biosciences, Inc.
US ˙ NasdaqGM ˙ US14843C1053

SecurityCSTL / Castle Biosciences, Inc.
InstitutionQUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series
Latest Disclosed Ownership49,217 shares
Latest Disclosed Value $ 1,005,011
QUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series reports 10.02% increase in ownership of CSTL / Castle Biosciences, Inc.

On August 26, 2025 - QUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series filed a NPORT-P form disclosing ownership of 49,217 shares of Castle Biosciences, Inc. (US:CSTL) valued at $1,005,011 USD as of June 30, 2025. The entity filed a previous NPORT-P on May 28, 2025 disclosing 44,734 shares of Castle Biosciences, Inc.. This represents a change in shares of 10.02% during the quarter. The current value of the position is $1,034,049 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2025-08-26 2025-06-30 NP Castle Biosciences EC US14843C1053 49,217 4,483 10.02 1,005 12.29 0.0226
2025-05-28 2025-03-31 NP Castle Biosciences EC US14843C1053 44,734 97 0.22 896 -24.73 0.0215
2025-02-25 2024-12-31 NP Castle Biosciences EC US14843C1053 44,637 -6,941 -13.46 1,190 -19.17 0.0260
2024-11-26 2024-09-30 NP Castle Biosciences EC US14843C1053 51,578 5,049 10.85 1,471 45.36 0.0278
2024-08-26 2024-06-30 NP Castle Biosciences EC US14843C1053 46,529 2,327 5.26 1,013 3.37 0.0206
2024-05-28 2024-03-31 NP Castle Biosciences EC US14843C1053 44,202 -2,057 -4.45 979 -1.90 0.0204
2024-02-26 2023-12-31 NP Castle Biosciences EC US14843C1053 46,259 4,368 10.43 998 41.16 0.0213
2023-11-28 2023-09-30 NP Castle Biosciences EC US14843C1053 41,891 -2 -0.00 708 23.17 0.0185
2023-08-25 2023-06-30 NP Castle Biosciences EC US14843C1053 41,893 2,375 6.01 575 -36.01 0.0136
2023-05-26 2023-03-31 NP Castle Biosciences EC US14843C1053 39,518 0 0.00 898 -3.55 0.0239
2023-02-24 2022-12-31 NP Castle Biosciences EC US14843C1053 39,518 -1,640 -3.98 930 -13.33 0.0256
2022-11-25 2022-09-30 NP Castle Biosciences EC US14843C1053 41,158 4,254 11.53 1,073 32.47 0.0308
2022-08-25 2022-06-30 NP Castle Biosciences EC US14843C1053 36,904 3,759 11.34 810 -45.49 0.0224
2022-05-26 2022-03-31 NP Castle Biosciences EC US14843C1053 33,145 0 0.00 1,487 4.65 0.0346
2022-02-25 2021-12-31 NP Castle Biosciences EC US14843C1053 33,145 0 0.00 1,421 -35.57 0.0308
2021-11-24 2021-09-30 NP Castle Biosciences EC US14843C1053 33,145 1,136 3.55 2,204 -6.09 0.0486
2021-08-26 2021-06-30 NP Castle Biosciences EC US14843C1053 32,009 10,115 46.20 2,347 56.68 0.0504
2021-05-27 2021-03-31 NP Castle Biosciences EC US14843C1053 21,894 2,731 14.25 1,499 16.49 0.0340
2021-02-25 2020-12-31 NP Castle Biosciences EC US14843C1053 19,163 0 0.00 1,287 30.56 0.0330
2020-11-25 2020-09-30 NP Castle Biosciences EC US14843C1053 19,163 1,853 10.70 986 51.07 0.0316
2020-08-27 2020-06-30 NP Castle Biosciences EC US14843C1053 17,310 2,058 13.49 652 43.61 0.0213
2020-06-01 2020-03-31 NP Castle Biosciences EC US14843C1053 15,252 9,619 170.76 455 135.23 0.0186
2020-02-27 2019-12-31 NP Castle Biosciences EC 14843C105 5,633 0 0.00 194 91.09 0.0058
2019-11-27 2019-09-30 NP Castle Biosciences EC US14843C1053 5,633 5,633 102 0.0034
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.