As crypto gains more acceptance — and also deals with a record number of hacks — insurance companies are getting into the game.

But according to Bloomberg, the premiums from insuring the risk can be substantial. In fact, it's been reported that underwriters can charge a crypto-related company as much as five times more than the average business for coverage against loss or theft.

“Insurance for cryptocurrency storage will be a big opportunity,” said Christian Weishuber, a spokesman for Allianz, which began offering individual coverage for digital-coin theft in the past year and is one of the few insurers that agreed to talk about the issue. “Digital assets are becoming more relevant, important and prevalent on the real economy and we are exploring product and coverage options in this area.”

Still, Marsh & McLennan and Aon, the two leading insurance brokers that help companies shop for crypto policies, are seeing some growth. Marsh recently formed a team dedicated to servicing blockchain startups, while Aon says it has over 50 percent of the market for crypto insurance.

In addition, American International Group has been adding crypto coverage into standard policy forms, and Lloyd’s of London, the world’s oldest insurance market, published a bulletin this month with guidance on crypto coverage and asked its agents to “proceed with a level of caution that recognizes the risks.”

So far, Marsh and Aon say they aren’t aware of any insurer that’s had to pay out crypto policy claims, despite the fact that 2018 is on track to be the busiest year for hacks on record.

While the cost is a hindrance, exclusions can also keep crypto companies from taking out a policy. For example, while losses from an interruption of service may be covered, the theft of cryptocurrency that caused it might not.

The number of exclusions “can make the whole policy close to useless,” said Hillik Nissani, chief operating officer of CRYPTALGO, which is currently looking to buy insurance or potentially self-insuring.

In addition, coverage amounts often fall short of the sums that could be lost during a hack. For example, Coinbase, one of the most widely used crypto exchanges, buys insurance for just a fraction of the digital coins it holds.