Cameron and Tyler Winklevoss, the brothers that pushed to introduce the first U.S. bitcoin exchange traded fund, the Winklevoss Bitcoin Trust, are looking to expand their Gemini Exchange to include more digital currencies.

After bitcoin, the largest cryptocurrencies are Ethereum, Ripple, Bitcoin Cash and Litecoin. Bitcoin futures debuted on the Cboe in December, followed by a launch on the CME. Nasdaq Inc. is still considering entering the bitcoin futures competition. Currently, Gemini offers trading in bitcoin and ethereum.

“Gemini has an exclusive deal to supply the data used to calculate Cboe’s Bitcoin contract,” reports Bloomberg. “Cboe could presumably add Ethereum now, given Gemini trades that, but expanding further would require Gemini widening its roster. Tyler Winklevoss said the licensing agreement with Cboe is scalable, and they entered into the deal knowing it could expand in terms of offerings.”

News of a potential Gemini expansion comes in the wake of announcements made earlier this week indicating more cryptocurrency investments are coming to market. For example, Coinbase, the operator of the largest U.S. cryptocurrency exchange, launched an index based on bitcoin and other digital currencies traded on Coinbase. The Coinbase Index Fund debuted Tuesday.

The fund is available only to accredited investors defined as those with an annual income of $200,000 or a net worth of $1 million or more. The minimum investment is $10,000 and the fund has an annual management fee of 2%, according to Coinbase.

Earlier this week, Grayscale Investments, the operator of the Bitcoin Investment Trust (OTCQX: GBTC) , introduced the Bitcoin Cash Investment Trust, Ethereum Investment Trust, Litecoin Investment Trust, and XRP Investment Trust.

“Adding Bitcoin cash and Litecoin would increase Gemini’s offerings to the same as Coindesk Inc., a major U.S. rival. That could boost the value of both: When Coinbase added coins in the past, the prices shot up,” according to Bloomberg.

Bitcoin is a decentralized digital currency, or cryptocurrency, based on a peer-to-peer network and can be exchanged through computers internationally without a financial intermediary. The system was first introduced by an unidentified programmer or group under the name of Satoshi Nakamoto in 2009.

For more information on the cryptocurrency, visit our Bitcoin category.