The virtual currency is down by close to 25% this week and almost 40% in 2018.
The second and third largest virtual currencies, Ethereum and Ripple, also plunged more than 20% at the session low, Coinmarketcap.com said. Ethereum was last down 18.2%, at $913.37, while Ripple last traded at 80 US cents, down 16.7%.
On Thursday, India vowed to eradicate the use of crypto-assets, joining China and South Korea in promising to ban parts of the nascent market where prices have boomed in recent years.
Social media website Facebook said this week it would ban cryptocurrency advertisements because many were associated with misleading or deceptive promotional practices. US regulators have sent a subpoena to two of the world’s biggest cryptocurrency players, Bitfinex and Tether.