|Analysis: Bitcoin futures highlight some pitfalls for new ETFs|
"There is no free lunch, however," said Martha Reyes, head of research at digital asset prime brokerage and exchange BEQUANT.
"An ETF based on futures is not ideal as there is a cost to rolling into the futures contracts, given contango ... translating into underperformance versus the underlying asset," she said.
Traders typically roll over futures to switch from the short-term contract that is approaching expiration to another contract further out in months. This rollover entails a cost.