CytomX Therapeutics, Inc.
US ˙ NasdaqGS ˙ US23284F1057

SecurityCTMX / CytomX Therapeutics, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership5,663,408 shares
Latest Disclosed Value $ 26,618,018
State Street Corp reports 10.16% increase in ownership of CTMX / CytomX Therapeutics, Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 5,663,408 shares of CytomX Therapeutics, Inc. (US:CTMX) valued at $26,618,018 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 5,140,931 shares of CytomX Therapeutics, Inc.. This represents a change in shares of 10.16% during the quarter. The current value of the position is $18,236,174 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-05-15 2026-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,663,408 522,477 10.16 26,618 21.54 0.0009
2026-02-13 2025-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,140,931 4,495,949 697.07 21,900 964.66 0.0007
2025-11-14 2025-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 644,982 5,942 0.93 2,057 41.86 0.0001
2025-08-14 2025-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 639,040 318,997 99.67 1,451 614.29 0.0001
2025-05-15 2025-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 320,043 0 0.00 203 -38.30 0.0000
2025-02-14 2024-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 320,043 56,400 21.39 330 5.79 0.0000
2024-11-14 2024-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 263,643 0 0.00 311 -3.12 0.0000
2024-08-14 2024-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 263,643 -3,833 -1.43 322 -44.94 0.0000
2024-05-15 2024-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 267,476 0 0.00 583 40.82 0.0000
2024-02-14 2023-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 267,476 0 0.00 415 20.00 0.0000
2023-11-14 2023-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 267,476 0 0.00 345 -25.00 0.0000
2023-08-14 2023-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 267,476 0 0.00 460 14.14 0.0000
2023-05-15 2023-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 267,476 43,500 19.42 404 12.57 0.0000
2023-05-15 2022-12-31 13F/A-99 CYTOMX THERAPEUTICS COM 23284F105 223,976 0 0.00 358 10.15 0.0000
2023-05-15 2022-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 223,976 0 358 0.0000
2022-11-15 2022-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 223,976 0 0.00 325 -20.73 0.0000
2022-08-15 2022-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 223,976 -974,706 -81.31 410 -87.19 0.0000
2022-05-16 2022-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 1,198,682 -1,540,862 -56.25 3,200 -73.02 0.0002
2022-02-14 2021-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 2,739,544 -1,297,393 -32.14 11,862 -42.27 0.0006
2021-11-15 2021-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 4,036,937 -579,625 -12.56 20,548 -29.69 0.0011
2021-08-16 2021-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 4,616,562 1,257,697 37.44 29,223 12.55 0.0015
2021-07-09 2021-03-31 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 3,358,865 1,308,268 63.80 25,964 93.31 0.0015
2021-05-17 2021-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 3,358,865 1,308,268 25,964 0.0015
2021-02-16 2020-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 2,050,597 -98,657 -4.59 13,431 -6.03 0.0008
2020-11-10 2020-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 2,149,254 -46,395 -2.11 14,293 -21.85 0.0010
2020-08-14 2020-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 2,195,649 1,208,701 122.47 18,290 141.61 0.0013
2020-06-19 2020-03-31 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 986,948 -2,622 -0.26 7,570 -7.94 0.0007
2020-05-11 2020-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 986,948 -2,622 7,570 664.7984
2020-02-06 2019-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 989,570 -551,119 -35.77 8,223 -27.68 0.0006
2019-11-14 2019-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 1,540,689 -192,764 -11.12 11,370 -41.54 0.0008
2019-08-14 2019-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 1,733,453 -361,032 -17.24 19,449 -13.62 0.0015
2019-05-15 2019-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 2,094,485 554,535 36.01 22,516 -3.17 0.0018
2019-02-12 2018-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 1,539,950 -441,600 -22.29 23,253 -36.57 0.0021
2018-11-09 2018-09-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 1,981,550 269,429 15.74 36,658 -6.34 0.0028
2018-08-14 2018-06-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 1,712,121 559,163 48.50 39,138 19.30 0.0033
2018-05-15 2018-03-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 1,152,958 61,142 5.60 32,805 42.34 0.0028
2018-02-14 2017-12-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 1,091,816 237,798 27.84 23,047 48.49 0.0019
2017-11-14 2017-09-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 854,018 407,703 91.35 15,521 124.49 0.0013
2017-08-14 2017-06-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 446,315 165,342 58.85 6,914 42.50 0.0006
2017-05-15 2017-03-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 280,973 5,490 1.99 4,852 60.29 0.0004
2017-02-09 2016-12-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 275,483 4,596 1.70 3,027 -28.74 0.0003
2017-01-13 2016-09-30 13F/A-1 CYTOMX THERAPEUTICS Common equity shares 23284F105 270,887 16,386 6.44 4,248 63.45 0.0004
2016-11-14 2016-09-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 270,887 4,248
2016-08-12 2016-06-30 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 254,501 162,724 177.30 2,599 119.88 0.0003
2016-05-20 2016-03-31 13F/A-1 CYTOMX THERAPEUTICS Common equity shares 23284F105 91,777 23,698 34.81 1,182 -16.82 0.0001
2016-05-12 2016-03-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 91,777 1,182
2016-02-16 2015-12-31 13F CYTOMX THERAPEUTICS Common equity shares 23284F105 68,079 68,079 1,421 0.0002
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.