Personally I don't like ETF's that are supposed to mirror indexes or currencies, the impact of the fees always seem to impact performance far in excess than the stated %.
If I was going to look at investing I would go through the historical movements & compare them to the actual NASDAQ movements X 2.6, especially when there has been a significant fall. In particular when the index falls from x to y & then rises from y back to x does the ETF return to the same point at the same time? In theory it should. I looked at BBUS (Leveraged bear S&P) & when I compared the above consistently the ETF did not return to the same level even over a period of just a few weeks. If you get year on year 10% growth in the NASDAQ it won't be uniform so the impact of ups & downs is important. The problem is a lack of history in this ETF especially for very volatile times in the index.
If you get 10% growth in the NASDAQ each year I wouldn't expect to see 26% each year from the ETF, although you should still get 20%+.
