* Buying seen at 200-day moving average -analysts
* Since peak, bitcoin has fallen more than 30% (Updates prices, adds analyst comment)
By Alun John, Tom Wilson and Gertrude Chavez-Dreyfuss
NEW YORK/LONDON/HONG KONG, Dec 6 (Reuters) - Bitcoin dropped by almost 5% on Monday as the start of the week offered little respite to the world's largest cryptocurrency after a bruising weekend when, at one point, it lost over a fifth of its value.
The rout sent bitcoin's price and the amount invested in bitcoin futures back to where they were in early October, before a massive price surge that sent the token to an all-time high of $69,000 on Nov. 10. Since that record peak, bitcoin has plunged 32%. It was last down 1.1% at $48,900.
Traders said the weekend fall was connected to a broad move away from riskier assets in traditional markets over worries about the Omicron variant of the coronavirus, combined with lower trading liquidity that tends to plague cryptocurrencies at weekends.
There was strong buying support, however, at the 200-day moving average, market participants said, with bitcoin fluctuating between $48,000 and $49,000.
Sean Farrell, head of digital asset strategy, at Fundstrat cited bitcoin's "outsized correlation to macro uncertainty," compared with the rest of the crypto market.
"We think this speaks to the overwhelming level of institutionalization of bitcoin over the prior 12 months as well as the independent market dynamics throughout the rest of crypto," Farrell said.
"This might explain why there was so much capitulation in bitcoin markets ... as legacy institutions look to preserve annual gains heading into year-end," he added.
Crypto data platform Coinglass showed open interest - the total number of futures contracts held by market participants at the end of the trading day - across all exchanges was last at $16.5 billion compared with $23.5 billion on Thursday, and as much as $27 billion on Nov 10.
"There's barely any liquidity on weekends so markets are slightly more vulnerable to shocks - that and a lot of demand coming from institutionals, and they're not trading over the weekend," said Joseph Edwards, head of research at crypto brokerage Enigma Securities in London.
Over the weekend, as prices fell, investors who had bought bitcoin on margin saw exchanges close their positions, causing a cascade of selling. A range of retail-focused exchanges closed more than $2 billion of long bitcoin positions on Saturday, according to Coinglass.
Some exchanges allow traders to place bets 20 times or more the size of their investment, meaning a small move in the wrong direction can cause exchanges to liquidate clients' positions when their initial investment is gone.
Ben Caselin at Asia-based crypto exchange AAX said liquidity had become thin because bitcoin moved off exchanges to offline digital wallets.
Ether, the world's second-largest cryptocurrency, was also hit on Saturday, albeit less hard. It tumbled 3.1% on Monday however to $4,070 versus its Nov. 10 high of $4,868.
On Sunday, one ether rose to as high as 0.086 bitcoin , its highest since May 2018.
(Reporting by Alun John in Hong Kong, Tom Wilson in London and Gertrude Chavez-Dreyfuss in New York, Editing by Gerry Doyle, Carmel Crimmins and Nick Zieminski)