Bitcoin futures fell in low volume Tuesday in their second day of trading on the Cboe Futures Exchange.

Trading volume in the most popular contract, which expires in January, was less than half what it was the prior day at just over 1,500 around the 4:15 p.m., ET, settle. Volume had already topped 800 about two hours after the futures launch Sunday night and was near 3,000 by 9:30 a.m. Monday morning.

The Cboe bitcoin futures, listed under the ticker XBT, settled 2.83 percent lower at $18,020 after earlier falling more than 3.5 percent. The contract had soared nearly 20 percent in its Monday debut, with a total 4,127 contracts traded and about 20 firms participating, according to Cboe.

However, some of the largest banks, such as Goldman Sachs, offered limited to no support for the Cboe bitcoin futures as of Monday.

A Cboe spokesperson said the exchange did not have a separate statement on Tuesday's trading volume, but noted that its CEO and Chairman Ed Tilly has said Cboe expects a slow and steady increase in the bitcoin futures' volume and open interest.

Open interest in the bitcoin futures was 1,372 Monday, versus 650,765 for Cboe Volatility Index (.VIX) futures, according to Cboe.

Bitcoin briefly rose more than 5 percent to a high of $17,615.47, according to CoinDesk's bitcoin price index, which tracks prices from digital currency exchanges Bitstamp, Coinbase, itBit and Bitfinex. The digital currency has surged about 1,700 percent this year as investor interest has grown despite criticism that bitcoin is in a bubble.

The gains came despite two of the largest exchanges for U.S. dollar-bitcoin trading reporting technical issues Tuesday.

A spokesperson for Coinbase, one of the leading platforms in the U.S. for buying and selling bitcoin, said in a statement that "the site is seeing high traffic volume at the moment and some users may be experiencing intermittent service outages." Coinbase's GDAX exchange website also said there is a "partially degraded service," as of 4:23 p.m., ET.

Coinbase also said in a 12:01 p.m. status update that, after about one-and-a-half hours, it had resolved an issue that temporarily disabled the purchase and sale of digital currencies ethereum and litecoin. The company reported a second suspension of ethereum buys and sells for about 45 minutes later in the afternoon.

Ethereum briefly surged more than 23 percent Tuesday to a record high of $637.62, according to CoinMarketCap, while litecoin temporarily climbed 59.5 percent for the day to a record high of $341.72. The bitcoin offshoot, bitcoin cash, jumped more than 14 percent to $1,628.95, according to CoinMarketCap.

Litecoin seven-day performance

Source: CoinMarketCap

"Because bitcoin might see more stability [due to Sunday's futures launch], we might see more activity in the other coins that don't have a derivatives market," said Paul Puey, CEO of Edge, which sells software for buying, selling, storing and transacting bitcoin securely. Edge has about 700,000 accounts and is adding about 1,000 a day, Puey said.

Another major exchange, Bitfinex tweeted Tuesday morning that it is once again under a DDoS, or distributed denial-of-service attack, which attempts to paralyze a system with a flood of information.

Tweet

Bitfinex has suffered a "sustained denial of service attack" since last week and took the website down briefly Tuesday "to mitigate further issues for customers," an exchange spokesperson said in a statement to CNBC. "We are constantly improving our systems to ensure that we're able to both accommodate the immense volume of trading that occurs on our platform while also fending off sustained DDoS attacks."

Bitfinex had the largest share of U.S. dollar-bitcoin trading volume late Tuesday afternoon at 28 percent, while Coinbase had about 24 percent, according to CryptoCompare.

Cboe's bitcoin futures launch comes a week ahead of CME's own product in a race by major exchanges to launch bitcoin derivatives. Cantor Fitzgerald and Nasdaq are also planning their own derivatives products.

Cryptocurrency enthusiasts say the launch of bitcoin derivatives will allow institutional investors to buy into the digital currency trend, helping establish bitcoin as a legitimate asset class and pave the way for an exchange-traded fund. VanEck refiled for a bitcoin ETF on Monday.