Financial Highlights Per Share Performance - Summary of Per Share Data (Details) - $ / shares	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Per Share Data:
Principal market net asset value, beginning of year	$ 17.18	$ 10.96	$ 23.19
Net increase (decrease) in net assets from investment operations
Net investment loss	(0.62)	(0.34)	(0.71)
Net realized and unrealized gain (loss)	16.65	6.56	(11.52)
Net increase (decrease) in net assets resulting from operations	16.03	6.22	(12.23)
Principal market net asset value, end of year	$ 33.21	$ 17.18	$ 10.96
Total return	93.31%	56.75%	(52.74%)
Ratios to average net assets:
Net investment loss	(2.50%)	(2.50%)	(2.50%)
Expenses	(2.50%)	(2.50%)	(2.50%)