It may be a while before the Securities and Exchange Commission approves a bitcoin exchange-traded fund, but cryptocurrency hedge-fund manager Dan Morehead says investors are overreacting to the news of a delay. "I still think it will be quite a long time until an ETF is approved. The last asset class to be approved for ETF certification was copper, and copper has been on earth for 10,000 years," the Pantera Capital CEO said Wednesday on CNBC's "Fast Money."