SecondMarket founder Barry Silbert is stepping down as SecondMarket CEO to focus exclusively on Bitcoin.

He'll remain Chairman and CEO of SecondMarket Holdings, Inc., but now plans to spin off the firm's digital currency activities. Silbert has been a leading cryptocurrency evangelist, and is currently planning on launching the first U.S. Bitcoin exchange network. He's also invested millions of dollars in cryptocurrency startups through his Bitcoin Opportunity Corp. venture capital fund.

"My passion for Bitcoin is no secret and I feel it is the right time to make this transition," he said in a statement. "Our intention is to formally separate the two business lines at the appropriate point in time. "

Bill Siegel has been appointed interim SecondMarket CEO.

In previous years, SecondMarket was known as a market for buying and selling shares of fast-growing private companies like Facebook, Twitter and Zynga.

Here's Silbert's full statement:

Believe it or not, it was ten years ago that I founded the company that would later be renamed SecondMarket. Over the past decade, SecondMarket has gained tremendous experience breaking open new markets such as private company stock, auction rate securities, bankruptcy claims, community bank stock and, most recently, bitcoin. The competencies and lessons learned opening these markets has been invaluable.

As with all startups, we have had some fantastic successes and some clear failures. But along the way, SecondMarket successfully transitioned from a telephone-based broker of illiquid assets into a highly scalable, product-focused organization that has redefined how private companies and funds raise capital and facilitate liquidity for their stakeholders. We have product market fit, a fantastic team, a record number of private company/fund customers and are very well positioned for long term success. The future for SecondMarket has never been brighter.

While I have never been more excited about SecondMarket, I have chosen to move on from day-to-day management of the private company/fund business so that I can focus 100% of my energy on our digital currency business. My passion for bitcoin is no secret and I feel it is the right time to make this transition. Our intention is to formally separate the two business lines at the appropriate point in time. In the meantime, I will remain Chairman and CEO of our parent holding company.

Bill Siegel, who has been instrumental in the development and refocusing of our private issuer products, has been appointed Interim CEO of that business line. Our clients are in great hands with Bill at the helm, and we are running a formal search for a permanent CEO for our private company business, in which Bill is a candidate.