The ETF pioneered by the Winklevoss twins could have increased liquidity for the bitcoin market and made exposure to the currency easier to attain. The price of bitcoin is down $200 as a result of the SEC's decision.
The U.S. Securities and Exchange Commission today decided not to mainstream bitcoin, by ruling that it will not permit the public listing of an ETF (exchange traded fund) that would have effectively allowed people to buy and sell the digital currency like stock. What? The SEC disapproved a request to allow the BATS stock exchange to list the Winklevoss Bitcoin Trust ETF, which was founded back in 2013 by the Winklevoss Brothers of Facebook (and The Social Network) fame. It also may dump a giant roadblock in the way of other future publicly-traded bitcoin investment vehicles. For example, the future is now a bit fuzzier for Barry Silbert's Bitcoin Investment Trust, which recently filed for a $500 million IPO (although it's structured differently from Winklevoss, and is already publicly traded on the OTC).
https://www.axios.com/sec-kills-winklevii-bitcoin-etf-2309635551.html