Bitcoin futures soar as the virtual currency begins trading on a major exchange

Wall Street got its first taste of bitcoin Monday, with the price of the first-ever futures contract for the digital currency jumping 20%.

It's a step forward for the bitcoin, which has soared this year despite concerns that the surge of investor interest has transformed it from a new-age currency into just the latest speculative bubble.

One prominent securities regulator said people were taking out second mortgages on their homes to buy bitcoin.

The January contract for bitcoin futures closed at $18,545 on the CBOE Futures Exchange. Trading began Sunday and the price rose as high as $18,850, according to data from CBOE.