The cryptocurrency market may be just what is needed to lure millennials into trading, TD Ameritrade chief market strategist JJ Kinahan told CNBC on Monday.

Digital currencies fell on Monday but have made huge gains over the past year.

"People complain that we haven't gotten millennials to trade. Maybe this isn't the product I'd like people to start with, but this is the greatest opportunity we've had in the market to get people who weren't traditionally interested in the market," he said in an interview with "Closing Bell."

Over the past year, bitcoin — the biggest cryptocurrency by market cap — is up more than 1,500 percent. Ripple, meanwhile, ripped 35,000 percent last year alone.

The steep rise of bitcoin has led some, such as J.P. Morgan Chase CEO Jamie Dimon, to call bitcoin a "fraud" and others to declare it is in a bubble.

Last month, TD Ameritrade announced it was offering clients access to Cboe's bitcoin futures, which began trading in December.

The company is one of the top three retail brokerages, according to capital markets research and consulting firm Tabb.

Kinahan said the firm traditionally likes to advise clients to use 10 percent of their money to speculate, but what millennials are saying is they want to use 90 percent to speculate.

"Do I agree with that? Not necessarily, but for us to say 'you're wrong' is silly," he said. Instead, they'll ask what clients are comfortable investing in the stock market.

— CNBC's Fred Imbert and Evelyn Cheng contributed to this report.