Winklevoss Capital Management founders Cameron and Tyler Winklevoss got the thumbs down for what could have been the first cryptocurrency ETF on Thursday, as the Securities and Exchange Commission rejected their application for the “Winklevoss Bitcoin Trust” a second time.

The SEC rejected an application for the “Winklevoss Bitcoin Trust” last year, but the application was resubmitted in June, which included a proposed rule change. According to a release Thursday by the SEC, the agency said that it did not agree with the Winklevoss’ premise that cryptocurrency markets are “uniquely resistant to manipulation.”

In addition, the SEC rejected the resubmittal due to concerns regarding fraud and investor protection, citing that “it has not met its burden under the Exchange Act.”

Related: Cryptocurrency Versus Forex

A cryptocurrency-based ETF has not yet been received approval from the SEC. VanEck and SolidX filed a joint application for a bitcoin ETF, which was published for comment on July 2 has until August 16 for the SEC to take action on the proposal.

The price of Bitcoin was at $8,133.14 as of 5:30 p.m. ET–up over 30% since the end of July. Bitcoin has been powered by a tailwind of positive news regarding institutional investor interest from names, such as BlackRock. In addition, San Francisco-based asset management company Bitwise recently filed for “the first publicly-offered cryptocurrency index exchange-traded fund (ETF).”

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