C4 Therapeutics, Inc.
US ˙ NasdaqGS ˙ US12529R1077

SecurityCCCC / C4 Therapeutics, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership2,511,015 shares
Latest Disclosed Value $ 6,603,969
Citadel Advisors Llc ownership in CCCC / C4 Therapeutics, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 2,511,015 shares of C4 Therapeutics, Inc. (US:CCCC) valued at $6,603,969 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 447,808 shares of C4 Therapeutics, Inc.. This represents a change in shares of 460.73% during the quarter. The current value of the position is $9,667,408 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (CCCC) in the form of stock options. The firm currently holds call options representing 44,000 of underlying shares valued at $115,720 USD and put options representing 33,600 of underlying shares valued at $88,368 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

CCCC / C4 Therapeutics, Inc. Historical Put/Call Ratio
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 C4 THERAPEUTICS COM STK 12529R107 2,511,015 2,063,207 460.73 6,604 672.28 0.0009
2026-02-17 2025-12-31 13F C4 THERAPEUTICS COM STK 12529R107 447,808 -33,641 -6.99 855 -19.94 0.0001
2025-11-14 2025-09-30 13F C4 THERAPEUTICS COM STK 12529R107 481,449 481,449 1,069 0.0002
2025-05-15 2025-03-31 13F C4 THERAPEUTICS COM STK 12529R107 0 -28,616 -100.00 0 -100.00
2025-02-14 2024-12-31 13F C4 THERAPEUTICS COM STK 12529R107 28,616 -5,481 -16.07 103 -46.91 0.0000
2024-11-14 2024-09-30 13F C4 THERAPEUTICS COM STK 12529R107 34,097 -339,560 -90.87 194 -88.76 0.0000
2024-08-14 2024-06-30 13F C4 THERAPEUTICS COM STK 12529R107 373,657 39,139 11.70 1,726 -36.85 0.0003
2024-05-15 2024-03-31 13F C4 THERAPEUTICS COM STK 12529R107 334,518 287,304 608.51 2,733 927.44 0.0005
2024-02-14 2023-12-31 13F C4 THERAPEUTICS COM STK 12529R107 47,214 -346,728 -88.01 267 -63.66 0.0001
2023-11-14 2023-09-30 13F C4 THERAPEUTICS COM STK 12529R107 393,942 -275,540 -41.16 733 -60.24 0.0002
2023-08-14 2023-06-30 13F C4 THERAPEUTICS COM STK 12529R107 669,482 142,328 27.00 1,841 11.24 0.0004
2023-05-15 2023-03-31 13F C4 THERAPEUTICS COM STK 12529R107 527,154 147,654 38.91 1,655 -26.08 0.0004
2023-02-14 2022-12-31 13F C4 THERAPEUTICS COM STK 12529R107 379,500 249,713 192.40 2,239 96.75 0.0005
2022-11-14 2022-09-30 13F C4 THERAPEUTICS COM STK 12529R107 129,787 101,836 364.34 1,138 439.34 0.0003
2022-08-15 2022-06-30 13F C4 THERAPEUTICS COM STK 12529R107 27,951 -80,278 -74.17 211 -91.96 0.0001
2022-05-16 2022-03-31 13F C4 THERAPEUTICS COM STK 12529R107 108,229 -53,727 -33.17 2,626 -49.65 0.0005
2022-02-14 2021-12-31 13F C4 THERAPEUTICS COM STK 12529R107 161,956 121,621 301.53 5,215 189.40 0.0011
2021-11-15 2021-09-30 13F C4 THERAPEUTICS Cmn 12529R107 40,335 -70,443 -63.59 1,802 -57.01 0.0004
2021-08-16 2021-06-30 13F C4 THERAPEUTICS COM STK 12529R107 110,778 90,527 447.02 4,192 459.68 0.0009
2021-05-21 2021-03-31 13F/A-1 C4 THERAPEUTICS COM STK 12529R107 20,251 -83,622 -80.50 749 -78.23 0.0002
2021-05-17 2021-03-31 13F C4 THERAPEUTICS COM STK 12529R107 20,251 -83,622 749 0.0002
2021-02-16 2020-12-31 13F C4 THERAPEUTICS COM STK 12529R107 103,873 103,873 3,441 0.0009
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F C4 THERAPEUTICS COM STK Call 44,000 263.64 116 400.00 n/a n/a n/a
2026-02-17 2025-12-31 13F C4 THERAPEUTICS COM STK Call 12,100 23 n/a n/a n/a
2025-05-15 2025-03-31 13F C4 THERAPEUTICS COM STK Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F C4 THERAPEUTICS COM STK Call 25,700 -69.80 93 -81.03 n/a n/a n/a
2024-11-14 2024-09-30 13F C4 THERAPEUTICS COM STK Call 85,100 74.03 485 115.56 n/a n/a n/a
2024-08-14 2024-06-30 13F C4 THERAPEUTICS COM STK Call 48,900 -8.77 226 -48.51 n/a n/a n/a
2024-05-15 2024-03-31 13F C4 THERAPEUTICS COM STK Call 53,600 -42.37 438 -16.76 n/a n/a n/a
2024-02-14 2023-12-31 13F C4 THERAPEUTICS COM STK Call 93,000 981.40 525 3,400.00 n/a n/a n/a
2023-11-14 2023-09-30 13F C4 THERAPEUTICS COM STK Call 8,600 -72.87 16 -82.76 n/a n/a n/a
2023-08-14 2023-06-30 13F C4 THERAPEUTICS COM STK Call 31,700 7.82 87 -5.43 n/a n/a n/a
2023-05-15 2023-03-31 13F C4 THERAPEUTICS COM STK Call 29,400 206.25 92 64.29 n/a n/a n/a
2023-02-14 2022-12-31 13F C4 THERAPEUTICS COM STK Call 9,600 -38.46 57 -59.12 n/a n/a n/a
2022-11-14 2022-09-30 13F C4 THERAPEUTICS COM STK Call 15,600 39.29 137 63.10 n/a n/a n/a
2022-08-15 2022-06-30 13F C4 THERAPEUTICS COM STK Call 11,200 -45.37 84 -83.10 n/a n/a n/a
2022-05-16 2022-03-31 13F C4 THERAPEUTICS COM STK Call 20,500 10.81 497 -16.61 n/a n/a n/a
2022-02-14 2021-12-31 13F C4 THERAPEUTICS COM STK Call 18,500 160.56 596 88.01 n/a n/a n/a
2021-11-15 2021-09-30 13F C4 THERAPEUTICS Cmn Call 7,100 -67.28 317 -61.39 n/a n/a n/a
2021-08-16 2021-06-30 13F C4 THERAPEUTICS COM STK Call 21,700 821 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F C4 THERAPEUTICS COM STK Put 33,600 -13.18 88 20.55 n/a n/a n/a
2026-02-17 2025-12-31 13F C4 THERAPEUTICS COM STK Put 38,700 -28.86 74 -39.17 n/a n/a n/a
2025-11-14 2025-09-30 13F C4 THERAPEUTICS COM STK Put 54,400 121 n/a n/a n/a
2025-05-15 2025-03-31 13F C4 THERAPEUTICS COM STK Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F C4 THERAPEUTICS COM STK Put 103,100 451.34 371 250.00 n/a n/a n/a
2024-11-14 2024-09-30 13F C4 THERAPEUTICS COM STK Put 18,700 -82.84 107 -78.93 n/a n/a n/a
2024-08-14 2024-06-30 13F C4 THERAPEUTICS COM STK Put 109,000 -29.45 504 -60.14 n/a n/a n/a
2024-05-15 2024-03-31 13F C4 THERAPEUTICS COM STK Put 154,500 -27.43 1,262 4.99 n/a n/a n/a
2024-02-14 2023-12-31 13F C4 THERAPEUTICS COM STK Put 212,900 1,256.05 1,203 4,044.83 n/a n/a n/a
2023-11-14 2023-09-30 13F C4 THERAPEUTICS COM STK Put 15,700 726.32 29 480.00 n/a n/a n/a
2023-08-14 2023-06-30 13F C4 THERAPEUTICS COM STK Put 1,900 -24.00 5 -28.57 n/a n/a n/a
2023-05-15 2023-03-31 13F C4 THERAPEUTICS COM STK Put 2,500 -28.57 8 -65.00 n/a n/a n/a
2023-02-14 2022-12-31 13F C4 THERAPEUTICS COM STK Put 3,500 21 n/a n/a n/a
2022-08-15 2022-06-30 13F C4 THERAPEUTICS COM STK Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-16 2022-03-31 13F C4 THERAPEUTICS COM STK Put 14,200 344 n/a n/a n/a
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.