Onetime bitcoin skeptic Mark Cuban is warming to the digital currency world.

The billionaire is backing a new venture capital fund for cryptocurrency-related investments called 1confirmation. Founded by Nick Tomaino, former business development manager at Coinbase, the fund plans to raise $20 million, according to a Monday filing with the Securities and Exchange Commission.

"It's an interesting space that I [want] to get involved with and learn more" about, Cuban said in an email to CNBC Tuesday. He did not specify the size of his investment.

Cuban's opinion on digital currencies has changed fairly recently. In an Aug. 14 tweet, the Dallas Mavericks owner admitted he "might have to finally buy some" , contrasting with a June tweet that said he thought bitcoin was in a "bubble."

"Bias should be up because of finite supply. Until crypto or US politics intrude, and they will," he added in another tweet on Aug. 14.

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In late June, Cuban said he planned to participate in an initial coin offering by Unikrn, an online esports betting site in which he holds a stake.

Earlier that month, Cuban tweeted that he didn't know when or by how much the price of bitcoin, which has soared in value this year, would correct. He did acknowledge then that the blockchain technology backing bitcoin had value and that it "will be at the core of most transactions in the future. Healthcare, finance etc all will use it."

IBM announced Tuesday that it will work with major food companies such as Wal-Mart, Unilever, Tyson Foods, Dole and Kroger to "identify new areas where the global supply chain can benefit from blockchain."

However, bitcoin's surge and a rush of funds into initial coin offerings have attracted more investment attention.

Bitcoin has quadrupled in value this year and hit a record last Thursday of $4,522.13 with a market capitalization of about $74 billion, according to CoinDesk. Initial coin offerings, which are fundraising events used by cryptocurrency-related start-ups, have raised $1.37 billion so far this year, CoinDesk data showed.

Source: CoinDesk

The launch of the 1confirmation fund comes amid increased fundraising for cryptocurrency-related businesses.

On Aug. 10, digital currency storage and exchange company Coinbase announced it raised $100 million in private equity funding led by Dropbox investor IVP. That marks the largest single traditional funding round for a public blockchain or cryptocurrency start-up, according to CoinDesk.

Other participants in 1confirmation include Brendan Eich, creator of the JavaScript computer programming language; Balaji Srinivasan, board partner at technology venture capital firm Andreessen Horowitz, and David Vorick, who is building a blockchain-based cloud storage system called Sia. The fund's founder, Tomaino, is also a principal at venture fund Runa Capital.

Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank," which features Mark Cuban as a panelist.