Quarterly Statements of Operations - Schedule of Quarterly Statements of Operations (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Sep. 30, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
Sep. 30, 2024 |
Jun. 30, 2024 |
Mar. 31, 2024 |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Expenses: | |||||||||||
| Sponsor's Fee, related party | $ 1,031 | $ 1,440 | $ 1,179 | $ 1,511 | $ 1,758 | $ 1,435 | $ 1,973 | $ 1,991 | $ 5,161 | $ 7,157 | $ 5,476 |
| Net investment loss | (1,031) | (1,440) | (1,179) | (1,511) | (1,758) | (1,435) | (1,973) | (1,991) | (5,161) | (7,157) | (5,476) |
| Net realized and unrealized (loss) gain from: | |||||||||||
| Net realized gain on investment in ETC | 507 | 912 | 653 | 989 | 1,221 | 896 | 1,436 | 1,450 | 3,061 | 5,003 | 3,269 |
| Net change in unrealized appreciation/depreciation on investment in ETC | (76,662) | 17,154 | (1,424) | (94,019) | 60,640 | (45,236) | (121,879) | 137,726 | (154,951) | 31,251 | 68,838 |
| Net realized and unrealized (loss) gain on investment | (76,155) | 18,066 | (771) | (93,030) | 61,861 | (44,340) | (120,443) | 139,176 | (151,890) | 36,254 | $ 72,107 |
| Net (decrease) increase in net assets resulting from operations | $ (77,186) | $ 16,626 | $ (1,950) | $ (94,541) | $ 60,103 | $ (45,775) | $ (122,416) | $ 137,185 | $ (157,051) | $ 29,097 | |