The Securities and Exchange Commission has denied the application for the Winklevoss Bitcoin Trust ETF, in a stunning defeat for its founders, the Winklevoss Twins. In an order today, the commission found that the proposed fund was too susceptible to fraud, due to the unregulated nature of Bitcoin. The result is a major setback for the fund, and a frustrating false start for the crypto-currency at large.

The ETF is essentially a common stock fund pegged to the price of Bitcoin, allowing investors to purchase Bitcoin without the work of establishing a personal wallet. (In concrete terms, the ETFs investors will be buying shares whose price will always be the same as the the price of a single bitcoin, similar to an equivalent investment in gold or cattle.) Without a wallet, investors still won’t be able to spend Bitcoin, but they can buy and sell it at market price, adding more liquidity to the Bitcoin system overall.

Since the ETF is an investment tool, it requires approval from the SEC before it can be offered to the public. Many in the Bitcoin world were deeply unsure how the SEC would rule, with Fortune describing the odds of approval as “a coin toss.” Still, approval would have meant a massive new opportunity for the Bitcoin world, and some experts predicted the price of Bitcoin would double if the fund was approved.

Unfortunately for speculators, the commission ultimately concluded that the price of Bitcoin is still too vulnerable to manipulation for it to be certified. “Regulated markets related to the underlying asset provide a ‘necessary deterrent to manipulation,’” the commission wrote in its analysis. “To the extent there is some question as to the degree to which Bitcoin is subject to manipulation... regulated markets relating to Bitcoin would help answer that question and address instances of such manipulation.”

While today’s news is certainly disappointing for Bitcoiners, it won’t be the currency’s last shot at such a certification. There are still two other ETF proposals pending before the SEC, and there are significant differences that might allow either one to succeed where the Winklevoss proposal failed.