Pakistan, Feb. 28 -- Bitcoin fell to a 3-1/2-month low on Friday, dragged by uncertainty about U.S. President Donald Trump's tariff plans and crypto policy and flagging investor confidence after a $1.5 billion hack in rival coin ether.

Bitcoin, the world's largest cryptocurrency by market value, was last down more than 5% on the day at $79,666, trading below $80,000 for the first time since November 11.

"Bitcoin's fall below $80k shows that positive sentiments from a crypto-friendly administration and high-profile endorsements have run their course," said Joshua Chu, Co-Chair of the Hong Kong Web3 Association.

The world's largest cryptocurrency has shed a quarter of its market value since mid-December, when it topped $105,000 on optimi...