Cryptocurrencies have plunged across the board after South Korean exchange Coinrail disclosed it had been hacked on Sunday.

Bitcoin led the pack, dropping as much as 12 percent to a three-month low of $6,673.08 before recovering slightly to $6,781.20 as of 10:25 p.m. EDT.

Other leading cryptocurrencies all dropped by similar levels, with Ethereum down more than 11 percent, to $519.93; Ripple XRP down almost 11 percent, to 58 cents; and Litecoin down more than 9 percent, to $105.34.

Why the markets reacted savagely to the news of the hack, though, is a mystery when taking into account both the size of the Coinrail hack and what it consisted of.

Coinrail is a minor cryptocurrency exchange that primarily deals in a number of obscure tokens. According to Ethereum World News, the exchange currently ranks at 90th in terms of size and handles only $2.7 million in trades on average per day.

Stolen in the hack, officially dubbed a “cyberintrusion” by the company, were $19.5 million worth of NPXS tokens that were issued in an initial coin offering called Pundi X; $13.8 million in tokens relating to another ICO called Aston X; $5.8 million in tokens for something called Dent; and $1.1 million Tron tokens.

Coinrail said over several tweets that it was “working hard to recover the total amount of the leaked coins” and that its site would remain offline until it could undertake a full security audit to assure that those behind the hack could no longer access other tokens.

The hacking of cryptocurrency exchanges has spooked the market before. But they nearly always involved the hackers stealing bitcoin and other leading cryptos, such as the case with Bithumb and YouBit, both South Korean exchanges that had large amounts stolen from them last year.

Billy Bambrough at Forbes argued that “while the potential Coinrail hack is unlikely to be on the same scale as either of last year’s breaches, it will shake the confidence of many potential bitcoin investors at a troubled time for cryptocurrencies,” and that is certainly one possibility.

The alternative could be that with short selling making it possible for investors to profit off large declines, someone or a group of people have used the Coinrail news as a front to manipulate the price of bitcoin and other cryptocurrencies for profit.

We may never know for sure, but there’s really no other logical explanation as to why a small hack of an obscure exchange barely anyone has ever heard of, trading little-known cryptocurrencies, would trigger a massive price plunge in leading cryptocurrencies.

Image: Coinrail