The price of bitcoin and other leading cryptocurrencies dropped Wednesday as regulatory fears along with rumors that a major exchange had been hacked plunged the market into uncertainty again.

Leading the headlines was a statement from the U.S. Securities and Exchange Commission saying that cryptocurrency trading sites needed to be registered with the agency as exchanges. The call for regulation, an extension of the commission’s crackdown on the market that started in July, was justified on the grounds that cryptocurrencies meet the definition of a “security” under federal securities laws as their value rises and falls like a stock.

“If a platform offers trading of digital assets that are securities and operates as an ‘exchange,’ as defined by the federal securities laws, then the platform must register with the SEC as a national securities exchange or be exempt from registration,” the SEC said.

The call for registration comes a day after The Financial Crimes Enforcement Network, a bureau within the U.S. Department of the Treasury, published a letter warning that initial coin offerings need to register as a money transmitter and also comply with anti-money-laundering statutes and know-your-customer rules.

Further spooking markets were new rumors that Hong Kong-based cryptocurrency exchange Binance had been hacked, a repeat of similar rumors Feb. 8. The rumors first emerged in a Reddit post where users detailed suspicious activity in their accounts, including the unauthorized sale of cryptocurrency holdings.

Binance denied that it had been hacked. “All funds are safe,” Chief Executive Changpeng Zhao insisted in a tweet. “There were irregularities in trading activity, automatic alarms triggered. Some accounts may have been compromised by phishing from before. We are still investigating.”

A further update from Binance noted that “the only confirmed victims have registered API keys (to use with trading bots or otherwise).” As CoinTelegraph pointed out, those words indicate that the account issues are related to third-party tools.

Both the SEC announcement and the Binance rumors apparently caused bitcoin to plunge below $10,000, the first time it has traded at that price since Feb. 26. Bitcoin was trading at $9,739.59 as of 9:45 p.m. EST. The contagion spread across over leading cryptocurrencies as well, with Ethereum dropping by more than $40, to $741.25.

Disclosure: The author is currently #HODL on a small amount of Ripple XRP.

Photo: bruce_krasting/Flickr