Bitcoin fell 8% to $3,800.50 as of 9:10 AM ET (14:10 GMT) on the Investing.com Index.
Cryptocurrencies overall slipped to $129 billion at the time of writing from $142 billion on Sunday.
U.S. federal law agencies returned 27.7 bitcoin that was stolen in August 2016 from Bitfinex, Reuters reported. The exchange had been hacked and 120,000 bitcoin, worth about $72 million at the time, was stolen.
Bitfinex said the bitcoin will be converted to cash and distributed to 5,000 customers impacted by the hack.
The Bitfinex hack was one of many major thefts, including of Mt. Gox in 2014 and Coincheck in 2017, which contributed to investor concern about security of digital exchanges.
In 2018, $950 million worth of digital coins were stolen,U.S.-based cybersecurity firm CipherTrace said last month.
In other news, Bahrain’s central bank is one of the first in the Arab world to issue rules related to digital currency assets. The rules are in line with its plans to become one of the leading hubs for finances in the Middle East and North Africa, Bloomberg reported on Monday.
Meanwhile, South Korean exchange Coinbin, which took over hacked platform Youbit, filed for bankruptcy on Wednesday. The company owns users nearly $30 million and is planning to go out of business due to embezzlement from a senior executive, Business Korea reported.
The news comes as Canada-based Quadriga was also forced to file for bankruptcy when it failed to recover the password of its cold wallet after the sudden death of its CEO in December.