CytomX Therapeutics, Inc.
US ˙ NasdaqGS ˙ US23284F1057

SecurityCTMX / CytomX Therapeutics, Inc.
InstitutionFmr Llc
Latest Disclosed Ownership24,688,109 shares
Ownership 14.60%
Fmr Llc ownership in CTMX / CytomX Therapeutics, Inc.

2026-02-05 - Fmr Llc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 24,688,109 shares of CytomX Therapeutics, Inc. (US:CTMX). This represents 14.6 percent ownership of the company. In their previous filing dated 2025-11-07 , Fmr Llc had reported owning 20,519,967 shares, indicating an increase of 20.31 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-02-05 2026-02-05 13G/A 20,519,967 24,688,109 20.31 14.60 17.74
2025-11-07 2025-11-07 13G/A 15,396,200 20,519,967 33.28 12.40 33.33
2025-11-05 2025-11-05 13G/A 9,238,868 15,396,200 66.65 9.30 57.63
2025-08-06 2025-08-06 13G 2,138,778 9,238,868 331.97 5.90 24.45
2019-04-10 2019-04-10 13G/A 5,924,431 2,138,778 -63.90 4.74 -63.98
2019-02-13 2019-02-13 13G/A 5,761,294 5,924,431 2.83 13.16 -12.25
2018-02-13 2018-02-13 13G/A 5,460,352 5,761,294 5.51 15.00 0.00
2017-02-14 2017-02-14 13G/A 5,403,643 5,460,352 1.05 15.00 0.01
2016-02-12 2016-02-12 13G/A 5,231,677 5,403,643 3.29 15.00 0.12
2015-11-10 2015-11-10 13G 5,231,677 14.98

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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)
2026-05-15 2026-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 31,955,637 7,267,528 29.44 150,191 42.81 0.0079
2026-02-17 2025-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 24,688,109 9,291,909 60.35 105,171 114.14 0.0054
2025-11-13 2025-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 15,396,200 6,157,332 66.65 49,114 134.18 0.0026
2025-08-14 2025-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 9,238,868 9,130,557 8,429.94 20,972 30,741.18 0.0012
2025-05-12 2025-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 108,311 -198,472 -64.69 69 -78.41 0.0000
2025-02-13 2024-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 306,783 22,476 7.91 316 -5.97 0.0000
2024-11-13 2024-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 284,307 41,949 17.31 335 13.56 0.0000
2024-08-13 2024-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 242,358 59,281 32.38 296 -26.07 0.0000
2024-05-13 2024-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 183,077 -382,247 -67.62 399 -54.45 0.0000
2024-02-13 2023-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 565,324 -142,644 -20.15 876 -4.05 0.0001
2023-11-13 2023-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 707,968 -19,412 -2.67 913 -27.02 0.0001
2023-08-11 2023-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 727,380 21,683 3.07 1,251 17.46 0.0001
2023-08-11 2023-03-31 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 705,697 -10,949 -1.53 1,066 -7.07 0.0001
2023-05-11 2023-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 705,697 -10,949 1,066 0.0001
2023-02-13 2022-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 716,646 15,074 2.15 1,147 12.68 0.0001
2022-11-10 2022-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 701,572 -1,637 -0.23 1,017 -20.98 0.0001
2022-08-12 2022-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 703,209 1,392 0.20 1,287 -31.32 0.0001
2022-05-13 2022-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 701,817 165,382 30.83 1,874 -19.29 0.0001
2022-02-14 2021-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 536,435 -509,185 -48.70 2,322 -56.37 0.0002
2022-02-14 2021-09-30 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 1,045,620 0 0.00 5,322 -19.60 0.0004
2021-11-15 2021-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 1,045,620 0 5,322 0.0001
2021-08-13 2021-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 1,045,620 13 0.00 6,619 -18.10 0.0005
2021-05-14 2021-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 1,045,607 0 0.00 8,082 18.00 0.0007
2021-02-08 2020-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 1,045,607 220,700 26.75 6,849 24.87 0.0006
2020-11-13 2020-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 824,907 -4,066 -0.49 5,485 -20.58 0.0006
2020-08-24 2020-06-30 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 828,973 360 0.04 6,906 8.67 0.0008
2020-08-13 2020-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 828,973 360 6,906 169.6602
2020-05-14 2020-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 828,613 -5 -0.00 6,355 -7.70 0.0009
2020-02-07 2019-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 828,618 -56,108 -6.34 6,885 5.45 0.0008
2019-11-13 2019-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 884,726 -438,485 -33.14 6,529 -56.02 0.0008
2019-08-13 2019-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 1,323,211 -815,568 -38.13 14,847 -35.43 0.0017
2019-05-13 2019-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 2,138,779 -3,785,652 -63.90 22,992 -74.30 0.0028
2019-02-13 2018-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,924,431 -820,122 -12.16 89,458 -28.30 0.0123
2018-11-09 2018-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 6,744,553 900,927 15.42 124,774 -6.60 0.0140
2018-08-10 2018-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 5,843,626 51,953 0.90 133,586 -18.93 0.0158
2018-05-14 2018-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,791,673 30,379 0.53 164,774 35.48 0.0196
2018-02-12 2017-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,761,294 231,189 4.18 121,621 21.04 0.0143
2017-11-13 2017-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 5,530,105 17,646 0.32 100,482 17.60 0.0121
2017-08-29 2017-06-30 13F/A-1 CYTOMX THERAPEUTICS COM 23284F105 5,512,459 34,732 0.63 85,444 -9.68 0.0106
2017-08-11 2017-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 5,512,459 34,732 85,444
2017-05-11 2017-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,477,727 17,375 0.32 94,600 57.64 0.0120
2017-02-10 2016-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,460,352 17,090 0.31 60,009 -29.69 0.0080
2016-11-14 2016-09-30 13F CYTOMX THERAPEUTICS COM 23284F105 5,443,262 30,097 0.56 85,350 54.35 0.0114
2016-08-11 2016-06-30 13F CYTOMX THERAPEUTICS COM 23284F105 5,413,165 1,484 0.03 55,295 -20.79 0.0075
2016-05-16 2016-03-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,411,681 8,038 0.15 69,811 -38.10 0.0097
2016-02-12 2015-12-31 13F CYTOMX THERAPEUTICS COM 23284F105 5,403,643 5,403,643 112,773 0.0152
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.