Hal,
Take a look at FCG.
The futures guys have far more trading ops that etf players. They can trade the strip and set up nice spreads between the contracts. We are limited to spot and the near month contract which severly limits our ops. Add contango into the mix and it becomes a real challenge to grab any coin with an etf (especially the double leveraged ones).
I was watching ECA and wondering if you pulled the trigger yet.
Best,
S