A relatively small cryptocurrency exchange has halted deposit and withdrawal services after its CEO has reportedly gone missing.

The IDAX exchange posted an announcement earlier today saying it had halted some operations after its staff were unable to make contact with the global CEO.

The CEO is said to have taken access to the company’s cold wallets with them. At this point, it’s not known why the CEO has supposedly vanished.

According to CoinMarketCap, IDAX serviced some $500 million worth of Bitcoin trades over the past 24 hours — compared to top ranking exchange BitMEX, which serviced over $2 billion. (These are reported figures, so bear that in mind and exercise caution.)

IDAX says it’s still trying to get a hold of the situation and understand what is going on.

The cryptocurrency exchange says it’s drawing up an emergency plan.

It has advised all users to refrain from using its platform and services for the time being.

IDAX hasn’t stated the value of cryptocurrency held in its cold wallets. However, the announcement did say that the cold wallets stored “almost all cryptocurrency balances on IDAX [which] have been restricted.”

No timeline has been given in regard to the emergency plan or when services can expect to be back online.

This is a developing story.

Earlier this year, Gerald Cotten the CEO of Canadian cryptocurrency exchange QuadrigaCX reportedly passed away taking the company‘s private keys and $134 million worth of cryptocurrency with him.