The Winklevoss ETF Fund - its essentially just a depository receipt for 1 BTC per share of the fund, right?  There isn't any internal investing that's done to grow the fund?  The only source of gains is just gains in the exchange rate?

Two questions:
1 - How does this add value over Coinbase?
2 - What's to stop someone from setting up a counter-fund, denominated in BTC, that's pegged to the dollar as a shorting mechanism?  Or, what's to stop someone from setting up equivalent funds? 

Obviously getting anything related to BTC up on Nasdaq is a big deal, but I don't really see the point of this unless they're actively lending starting capital to exchanges, etc to generate some revenue.