Two fund managers are going back to U.S. securities regulators for permission to launch exchange-traded funds (ETFs) based on the bitcoin, filings showed on Monday, after Sunday's listing of futures contracts based on the digital currency,

REX Shares LLC and Van Eck Associates Corp. are both proposing bitcoin funds that would use futures to access the market instead of investing directly in them. Each firm declined to comment while the fund proposals are evaluated.

The U.S. Securities and Exchange Commission has denied or tabled all bitcoin ETF proposals received so far, but proponents think a successful debut of futures could revive the concept. Such funds could make it easier for investors to bet on bitcoin's price rising or falling.