This year will end without a bitcoin exchange traded fund coming to market in the U.S. and the near-term prospects for a US-listed exchange traded product linked to the largest cryptocurrency look increasingly dire following recent comments by Securities and Exchange Commission (SEC) Chair Jay Clayton.

Speaking at the Consensus Invest summit in New York, “Clayton expressed fresh concerns about digital currency ETFs, citing fears over theft and market manipulation,” reports Fortune.

Earlier this year, the SEC rejected the applications, preventing the digital currency from gaining more acceptance from investors who are wary of the unregulated exchanges of cryptocurrencies. The SEC’s Division of Trading and Markets rejected applications from investment firms ProShares, Direxion and GraniteShares.

In previously turning back the bitcoin ETF applications, the SEC stated, “Among other things, the Exchange has offered no record evidence to demonstrate that bitcoin futures markets are ‘markets of significant size.’ That failure is critical because, as explained below, the Exchange has failed to establish that other means to prevent fraudulent and manipulative acts and practices will be sufficient, and therefore surveillance-sharing with a regulated market of significant size related to bitcoin is necessary.”

SEC Chair Comments

“Clayton said he will only support ETFs—financial products that track assets such as gold or baskets of shares—in which the only risk to investors is related to the value of the underlying asset,” according to Fortune.

In June, ETF issuer VanEck and SolidX, a fintech company engaged in the bitcoin ecosystem, revealed plans for the VanEck SolidX Bitcoin Trust ETF (XBTC). That fund is targeted at institutional investors as it would debut with a share price of $200,000. That product would track an index linked to a group of bitcoin trading desks, possibly allaying some of the SEC’s prior concerns about funds linked to physical bitcoin.