A group of disgruntled investors is pursuing a formal claim against the cryptocurrency platform Binance for allegedly causing millions in damages through an unanticipated outage earlier this year. Filed in an international business arbitration court, the case represents the largest investor action ever brought against a cryptocurrency platform, and a major test of the rights of investors speculating in digital currency markets.

The case stems from a widespread service outage on May 19th, which coincided with a massive drop in the price of Bitcoin. Binance wasn’t the only platform affected, as a mass selloff clogged blockchain transactions and overwhelmed reserves, but the complex financial products offered by the platform made the damage particularly severe. By the time service had been restored, many futures and leverage traders on Binance had seen their entire accounts automatically emptied. The traders say that, if Binance had been capable of filling orders, they could have sold off before their holdings became worthless.

More than 700 people were affected by the freeze, and early participants in the new action include losses as large as $12 million. If the action is successful, Binance will have to make up those losses out of its own pocket, and accept a higher level of liability to investor claims going forward.

One participant in the new action, a Canadian investor named Fawaz, says he attempted to close his position as early as noon on May 19th — but the platform failure made it impossible. “I tried to click that Close Position button more than 70 times,” Fawaz said in a statement provided to reporters. “But it never worked. Eventually, my position got fully liquidated.” All told, he believes he lost $6 million because of the downtime.

Reached for comment, Binance emphasized the sector-wide nature of the outage. “On 19 May, nearly all cryptocurrency exchanges suffered temporary outages due to extreme market volatility,” a representative told The Verge. “At Binance, we took immediate steps to engage with users affected by the outage, and we worked quickly to restore trading.”

“Our policy is fair in that we compensate users who experienced actual trading losses due to our system’s issues,” the representative continued. “We do not cover hypothetical ‘what could have been’ situations such as unrealized profits.”

Simply finding a venue to hear the case was a challenge. Binance does not have a listed headquarters that could place it in a specific jurisdiction, which frustrated earlier attempts to file a traditional lawsuit against the company. Instead, the company’s terms of service request that all legal proceedings be handled through the Hong Kong International Arbitration Centre, a quasi-judicial body typically used to resolve transnational business disputes. The plaintiffs are hoping to bundle everyone affected by Binance outages into a single arbitration suit, minimizing court costs and giving investors like Fawaz their first shot at getting some of their money back.

“In no jurisdiction would this ever be allowed,” says David Kay, who is financing the action through his Liti Capital fund. “But they’re not subject to any jurisdiction.”

Kay and his partners have already assembled a steering committee, led by a handful of plaintiffs affected by the outage including Fawaz. But they’re hoping to attract more before taking the claim to Hong Kong, and encouraging anyone affected by a Binance outage to join the case through their website.

Most notorious for their role in US employment law, arbitration hearings differ from traditional trials in important ways. The investors’ action is not technically a lawsuit, and the concept of a “class action” is not applicable. Without a national body of law, arbitrators rely on international standards for business practice. Without a government upholding the system, the parties expected to bear significant costs for initiating proceedings, although the specifics of the costs can vary. But similar to conventional courts, the final ruling is binding, and the Hong Kong Arbitration Centre has significant powers to enforce payment if the investors’ claim is successful.

Founded in 2017, Binance has been wildly successful as a cryptocurrency platform, growing into the primary venue for more complex financial trading in cryptocurrency markets. The platform claims to process more than a million trades each second, generating billions of dollars in user fees. That success has come with significant regulatory issues. The platform is currently under investigation from both the US Department of Justice and Internal Revenue Service, and has been formally blocked from operating in the United Kingdom.

The recent action is unconventional in a number of ways, not least in how the plaintiffs are organizing their case. The case is being financed by Kay’s Liti Capital, which will assume the significant upfront costs for mounting the lawsuit. In exchange, the firm will receive a portion of any resulting settlement, similar to the contingency rate offered by plaintiff’s lawyers in the US. In a crypto-oriented twist, Liti is itself funded through a tokenized blockchain system, allowing more flexibility as investors seek to finance specific legal claims.

There’s a certain irony to using a blockchain-traded litigation firm to mount a lawsuit against a major cryptocurrency platform, but as Kay sees it, it’s all for the greater good of the blockchain.

“I want Binance to be successful,” says Kay. “I want the crypto industry to be successful. But we have to set some basic rules.”

Update 10:33 AM ET: Added statement from Binance.