Floyd Mayweather John Salangsang/AP Floyd Mayweather Jr. can't seem to shake the cryptocurrency bug.

The undefeated boxing champion took to Twitter Wednesday to promote another initial coin offering, the red-hot cryptocurrency-based fundraising method.

In July, Mayweather promoted the ICO of Stox.com, a blockchain prediction company. This time, he is supporting Hubii Network, a media tech company.

According to a tweet, Mayweather is also looking to go by a new nickname: "Floyd Crypto Mayweather."

Hubii, a content distribution company with 50 million customers, is looking to raise $50 million through an Ethereum-based initial coin offering, according to a press representative for the firm. The ICO will not be open to US investors.

Initial coin offerings are a new funding vehicle using blockchain, the technology behind bitcoin. The market for so-called ICOs is exploding, with over $1.86 billion raised via the method since the beginning of the year, according to data from Autonomous NEXT, a financial technology analytics provider. The massive growth of the ICO market has many people in the space thinking it's a bubble, with many firms using the method as a way to raise vasts amount of money without offering an actual product.

To raise money through an ICO, a company issues a new digital currency that can either be spent within its ecosystem, a bit like Disneyland dollars, or used to power part of the business.

Recently they've come under the scrutiny of the Securities and Exchange Commission. As a result, more and more companies running ICOs have limited participation to non-US investors. But that hasn't stopped some American investors from getting in on the ICO action, according to Josh Olszewicz, a bitcoin insider and investor.

"There are ways to work around this by essentially setting up your Ethereum address in another country," he told Business Insider during a visit to New York.

Olszwicz said he has never tried to do this, but he says it's not that difficult of a process for someone with the expertise.