Note 8 - Financial Highlights (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

Financial Highlights [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	2017			2016			2017			2016
Net asset value per Share, beginning of period	$	11.98		$	11.93		$	11.16		$	10.25
Net investment loss (a)		(0.01	)		(0.01	)		(0.01	)		(0.01	)
Net realized and unrealized gain (loss) (b)		(0.02	)		0.81			0.80			2.49
Net increase (decrease) in net assets from operations		(0.03	)		0.80			0.79			2.48
Net asset value per Share, end of period	$	11.95		$	12.73		$	11.95		$	12.73
Total return, at net asset value (c)(d)		(0.25	) %		6.71	%		7.08	%		24.20	%
Ratio to average net assets:
Net investment loss (e)		(0.25	) %		(0.25	) %		(0.25	) %		(0.25	) %
Expenses (e)		0.25	%		0.25	%		0.25	%		0.25	%