Bitcoin tumbles as 'sharks start to circle'

London - Bitcoin’s plunge extended to more than 25% on Friday as the frenzy surrounding digital currencies faced one of its biggest tests yet. 

The world’s largest cryptocurrency approached $10 000 as this week’s selloff entered a fourth day with increasing momentum. It touched a record high $19 511 on Monday. Other cryptocurrencies also tumbled, with bitcoin cash crashing more than 35% and ethereum losing more than 23% over the past 24 hours, according to coinmarketcap.com.

The losses represent a major test for the cryptocurrency industry and the blockchain technology that underpins it, which have rapidly entered the mainstream in recent weeks.

• READ: Bitcoin plummets toward $13 000, down over 30% from record

Bears cast doubt on the value of the virtual assets, with UBS Group AG this week calling bitcoin the “biggest speculative bubble in history”. Bulls argue the technology is a game changer for the world of investment and finance. Both will be closely watching the outcome of the current sell-off.

"The sharks are beginning to circle here, and the futures markets may give them a venue to strike,” said Ross Norman, chief executive officer of London-based bullion dealer Sharps Pixley, which offers gold in exchange for bitcoin.

“Bitcoin’s been heavily driven by retail investors, but there’ll be some aggressive funds looking for the right opportunity to hammer this thing lower.”

Traders who bought the currency on futures exchanges using collateral may start facing margin calls following the price decline. Two venues launched products in recent weeks that required hefty security, with Cboe needing 44% to clear contracts, and the CME 47%. Brokers set safety nets even higher.

• READ: Bitcoin may hit $10 000 by year-end

There’s no doubt people who got in on margin will face some pressure here,” Norman said by phone from London. “The volumes weren’t huge, so it won’t be a major price driver, but for those caught on the wrong side it will hurt.”

Many of the recent news stories and market moves connected to cryptocurrencies appear to carry hallmarks of the mania phase of a bubble.

Still, cryptocurrencies are attracting established players. Goldman Sachs is setting up a trading desk to make markets in digital currencies such as bitcoin, according to people with knowledge of the strategy. The bank aims to get the business running by the end of June, if not earlier, two of the people said.

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