v3.26.1
Financial Highlights Per Share Performance - Summary of Per Share Data (Detail) - $ / shares
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Per Share Data:        
Principal Market NAV, beginning of period $ 26.06 $ 41.21 $ 35.45 $ 41.67
Net increase (decrease) in net assets from investment operations:        
Net investment loss (0.01) (0.27) (0.02) (0.58)
Net realized and unrealized loss (5.83) 4.52 (15.21) 4.37
Net increase (decrease) in net assets resulting from operations (5.84) 4.25 (15.23) 3.79
Principal Market NAV, end of period $ 20.22 $ 45.46 $ 20.22 $ 45.46
Total return (22.41%) 10.31% (42.96%) 9.10%
Ratios to average net assets:        
Net investment loss (0.35%) (2.50%) (0.16%) (2.50%)
Gross expenses (0.35%) (2.50%) (0.35%) (2.50%)
Expenses (0.35%) (2.50%) (0.16%) (2.50%)