When it comes to bitcoin exchange traded funds, the one that gets the most attention is the yet-to-be listed Winkelvoss Bitcoin Trust, an ETF sponsored by twin brothers Cameron and Tyler Winkelvoss.

SecondMarket’s Bitcoin Investment Trust could beat its Winkelvoss rival to market. In fact, the Bitcoin Investment Trust has been available to accredited investors and has already amassed $70 million in assets under management, SecondMarket’s Barry Silbert told ETF Trends. The bulk of those inflows have come courtesy of family offices, tech entrepreneurs and Wall Street professionals, according to Silbert.

The Bitcoin Investment Trust is expected to list on the OTCQX in the fourth quarter and Silbert says the goal is to eventually list the Trust on a major U.S. exchange.

SecondMarket’s Bitcoin Investment Trust is comparable to commodities ETFs such as the SPDR Gold Shares (NYSEArca: GLDand the iShares Silver Trust (NYSEArca: SLV) in that the Trust ensures storage and safekeeping while focusing exclusively on a single asset.

Because the BIT already complies with FINRA statutes, it will be able to file to open the exchange on a much more accelerated timeline than the Winklevosses,” Business Insider reported in March.

Silbert said the Trust is receiving increased interest from registered investment advisors and wirehouses because, at the moment, bitcoin cannot be placed on traditional brokerage statements, but ETFs do not have that problem. Accredited investors can invest in the Trust through their IRAs and 401(k)’s, according to SecondMarket. [Bitcoin ETF to List on Nasdaq]

“Through established relationships our Authorized Participant has with the major bitcoin exchanges and large private pools of bitcoins, the BIT is able to offer a weighted price that reflects a more accurate market view. Investors can buy shares in the BIT at a set price and without having to transact in a fragmented and highly illiquid market with unregulated and newly established entities,” according to the Trust’s web site.

On Friday, the US Marshals Service will auction off nearly $18 million worth off seized bitcoin, an event that some market observers believe could further legitimize the digital currency.

ETF Trends editorial team contributed to this post. Tom Lydon’s clients own shares of GLD and SLV.