v3.26.1
Note 7 - Financial Highlights - Summary of Financial Highlights (Details) - $ / shares
 3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
Net Asset Value per Share, beginning of period (in dollars per share) $ 396.12 $ 241 $ 352.09 $ 243.01
Net investment income/(loss) (in dollars per share) [1] (0.44) (0.26) (0.83) (0.51)
Net Realized and Change in Unrealized Gain/(Loss) (in dollars per share) [2] 27.66 46.54 72.08 44.78
Net increase/(decrease) in net assets resulting from operations (in dollars per share) 27.22 46.28 71.25 44.27
Net Asset Value per Share, end of period (in dollars per share) 423.34 287.28 423.34 287.28
Market Value per Share, beginning of period (in dollars per share) 396.31 242.13 355.47 243.06
Market Value per Share, end of period (in dollars per share) $ 430.29 $ 288.14 $ 430.29 $ 288.14
Ratio to average net assets        
Net Investment loss [3] (0.40%) (0.40%) (0.40%) (0.40%)
Gross expenses [3] 0.40% 0.40% 0.40% 0.40%
Net expenses [3] 0.40% 0.40% 0.40% 0.40%
Total Return, at Net Asset Value [4] 6.87% 19.20% 20.24% 18.22%
Total Return, at Market Value [4] 8.57% 19.00% 21.05% 18.55%
[1] Based on average Shares outstanding during the period
[2] The amounts reported for a Share outstanding may not accord with the change in aggregate gains and losses on investment for the period due to the timing of Share transactions in relation to the fluctuating fair values of the Trust's underlying investment.
[3] Percentages are annualized.
[4] Percentages are not annualized.