Bitcoin prices surged Monday as contract futures for the cryptocurrency began trading Sunday evening on the Cboe Global Markets, the first traditional platform serving the currency.

Bitcoin contract futures opened at $15,000, and 890 contracts were traded in the first 2 hours and 15 minutes Sunday evening, according to the Chicago-based Cboe. The Cboe said 4,127 bitcoin futures contracts were traded in the first full day.

Cboe reported two trading halts overnight of Cboe Bitcoin Futures (XBT) due to heavy demand. One halt lasted two minutes, the other for five, according to a Cboe spokesman. There were no trading halts Monday.

“We are very pleased with the results so far,” said Michael Mollet, director of product development at Cboe. “The trading has been orderly. We hit a couple of our circuit-breaker halts, but those were due to price movement in futures and not due to any systems issues. We halted like our rules said we would and opened back up.”

Bitcoin values have skyrocketed more than 15-fold in 2017, and the digital currency has been on a tear, last week topping $17,000 a coin before settling back around $15,000. It has risen $5,000 in the past week.

The currency was back trading around $17,300 at 4 p.m. Monday, a 12.6 percent increase in 24 hours. The Cboe Futures Exchange daily settlement price for January bitcoin futures was $18,545 when the market closed Monday.

Bitcoin has become part of the national conversation, dominating Wall Street, the financial press and its broadcast arms. It even was included in a Saturday Night Live skit on Saturday.

“Despite fears by many of the bubble popping, so far the price is going up,” said J.R. Lanis, an attorney with Drinker Biddle. “The demand seems to be real. It is beyond just technologist speculators. You now have institutional investors participating in the market and keeping the price high. We will see if that continues.”

As bitcoin goes mainstream, industry observers said investors should be cautious.

“Digital currencies are volatile and the prices can go up and down,” said Brian Armstrong, chief executive at digital currency exchange Coinbase, in a blog. “Due to the rapidly changing price of digital currencies, some customers may not have sell limits that are sufficient relative to the value of total digital currency they are storing on Coinbase. Sell limits are one of the many measures Coinbase takes to protect client accounts and assets.”