Note 7 - Financial Highlights - Summary of Financial Highlights (Details) - $ / shares |
3 Months Ended | 9 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Net Asset Value per Share, beginning of period (in dollars per share) | $ 423.34 | $ 287.28 | $ 352.09 | $ 243.01 | ||||||||
| Net investment income/(loss) (in dollars per share) | [1] | (0.41) | (0.3) | (1.24) | (0.81) | |||||||
| Net Realized and Change in Unrealized Gain/(Loss) (in dollars per share) | [2] | (53.46) | 15.89 | 18.62 | 60.67 | |||||||
| Net increase/(decrease) in net assets resulting from operations (in dollars per share) | (53.87) | 15.59 | 17.38 | 59.86 | ||||||||
| Net Asset Value per Share, end of period (in dollars per share) | 369.47 | 302.87 | 369.47 | 302.87 | ||||||||
| Market Value per Share, beginning of period (in dollars per share) | 430.29 | 288.14 | 355.47 | 243.06 | ||||||||
| Market Value per Share, end of period (in dollars per share) | $ 368.38 | $ 304.83 | $ 368.38 | $ 304.83 | ||||||||
| 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] | (12.72%) | 5.43% | 4.94% | 24.63% | |||||||
| Total Return, at Market Value | [4] | (14.39%) | 5.79% | 3.63% | 25.41% | |||||||
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