HONG KONG/SINGAPORE - Cryptocurrency markets nursed heavy losses on Thursday, with bitcoin pinned near a two-year low as investors fretted about the fallout from the implosion of crypto exchange FTX.

Larger rival Binance walked away from a bailout deal on Wednesday. FTX head Sam Bankman-Fried said he was "exploring all the options", but fading hopes for rescue left FTX teetering. A message on the FTX website said: "FTX is currently unable to process withdrawals. We strongly advise against depositing."

Focus is on the unknown size of customer losses and the hit to sentiment from the latest and possibly largest collapse in an industry that has turned into a minefield for investors.

FTX's native token, FTT is down 90% this week and was attempting to steady around $2 -- not terribly far above its record low around $1.50. Bitcoin fell below $16,000 for the first time since late 2020 overnight and was last at $16,435.

Binance backed out of a non-binding offer to buy FTX after due diligence. Another exchange, OKX, said it was also approached by Bankman-Fried this week, who described liabilities of $7 billion that needed covering quickly.

"Even Elon Musk would not be able to commit to a deal with $7 billion liability within a few hours of negotiations. That was too much for us," Lennix Lai, director of financial markets at OKX told Reuters.

"(It) is a big hole to plug," he added. "The dagger will continue to hang over the crypto market, as long as the outlook of FTX's fate remains unclear."

The Wall Street Journal reported that Bankman-Fried told investors FTX needed $8 billion to cover withdrawals. FTX did not respond to a request for comment.

'CONFIDENCE CRISIS'

There are also early signs that the fallout could spread beyond crypto markets, with jittery stockmarkets sliding on Wall Street overnight.

"A top exchange failing - that's on a different level," said Danny Chong, CEO of decentralised finance firm Tranchess, with potentially wider ramifications than the failure of stablecoin TerraUSD and crypto hedge fund Three Arrows Capital this year.

"People's funds, including market makers', are still currently with FTX," he said. "Just when people were thinking that crypto winter might probably not last ... along comes another episode like this."

The U.S. securities regulator is investigating FTX.com's handling of customer funds and crypto-lending activities, according to a source with knowledge of the inquiry.

Bloomberg reported that the U.S. Department of Justice is also looking in to the turmoil. A DOJ spokesperson declined to comment.

Investors are already writing off funds ploughed into FTX. Venture capital fund Sequoia Capital wrote down a $150 million exposure to zero on Wednesday. Canada's Ontario Teachers Pension Plan, Tiger Global and Japan's Softbank are also FTX investors.

Most crypto players remain bullish about the long term, but are braced for further falls in the near future. Bitcoin's 20%losses this week are comparable to the drop in June when Three Arrows Capital came under stress.

"What makes this new phase ... problematic is that the number of entities with stronger balance sheets able to rescue those with low capital and high leverage is shrinking," analysts at J.P. Morgan

"Now that the balance sheet strength of Alameda Research and FTX is under question only a few months after being perceived as strong balance sheet entities, it creates a confidence crisis and reduces the appetite of other crypto companies to come to the rescue."

(Reporting by Georgina Lee in Hong Kong and Tom Westbrook in Singapore. Editing by Shri Navaratnam)