's wild spikes this week are unlikely to be repeated next week or by other cryptocurrencies, according to a bitcoin security expert.

"The first time a new thing is launched, then it becomes extremely important for the reaction of the market. Next time, so let's say the next future being launched, [you'll] probably not see a big reaction there," Michael Gronager, CEO of bitcoin security firm Chainalysis, told CNBC's "Squawk on the Street" on Friday.

Bitcoin skyrocketed past $19,000 this week in a , rising largely on the news that bitcoin futures would begin trading on official exchanges.

Chicago-based is planning to launch bitcoin futures on Sunday, while the world's largest futures exchange, , is set to launch its futures product the following week.

Gronager said you can expect volatility in the price next week but not the "crazy movements" we saw this week.

And any traders looking to buy into alternative cryptocurrencies such as ethereum in anticipation of an eventual futures launch might reconsider: "It's hard to say if the same thing will apply," Gronager said.

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