v3.25.4
Statements of Changes in Net Assets - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Mar. 31, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Decrease (increase) in net assets from operations:              
Net investment loss $ (1,031) $ (1,511) $ (1,758) $ (1,991) $ (5,161) $ (7,157) $ (5,476)
Net realized gain on investment in ETC 507 989 1,221 1,450 3,061 5,003 3,269
Net change in unrealized appreciation (depreciation) on investment in ETC (76,662) (94,019) 60,640 137,726 (154,951) 31,251 68,838
Net (decrease) increase in net assets resulting from operations         (157,051) 29,097 66,631
Increase in net assets from capital share transactions:              
Shares issued         0 0 0
Net increase in net assets resulting from capital share transactions         0 0 0
Total (decrease) increase in net assets from operations and capital share transactions         (157,051) 29,097 66,631
Net assets:              
Beginning of year   $ 283,055   $ 253,958 283,055 253,958 187,327
End of year $ 126,004   $ 283,055   $ 126,004 $ 283,055 $ 253,958
Change in Shares outstanding:              
Shares outstanding at beginning of year   13,993,800   13,993,800 13,993,800 13,993,800 13,993,800
Shares issued         0 0 0
Net increase in Shares         0 0 0
Shares outstanding at end of year 13,993,800   13,993,800   13,993,800 13,993,800 13,993,800