* Futures launch may confer legitimacy on the cryptocurrency
* Big U.S. banks, brokerages give launch a mixed reception
* Futures indicate less heady growth to come (Recasts, adds quote, updates prices)
NEW YORK/SYDNEY/LONDON, Dec 11 (Reuters) - Newly launched bitcoin futures indicated on Monday that financial markets expect the cryptocurrency to climb further but at a far slower rate than in recent weeks as warnings of a bubble grew.
Chicago-based derivatives exchange Cboe Global Markets launched its eagerly anticipated bitcoin futures late on Sunday, marking the first time investors could get exposure to the market via a large mainstream regulated exchange.
Bitcoin futures were already offered on some unregulated cryptocurrency exchanges outside the United States, but backers said this U.S. market debut would confer greater legitimacy on the volatile cryptocurrency and lead to its wider use.
The one-month bitcoin contract opened at 6 pm local time (2300 GMT) on Sunday at $15,460, dipped briefly before rising to a high of $18,700 and then slipping again.
By 1418 GMT on Monday, just over 15 hours after it had began trading, the one-month future contract was trading at $17,910, just 10 percent above bitcoin's "spot" price - the price at which it is currently changing hands - which was $16,450 on the Bitstamp exchange.
Given that bitcoin has almost tripled in value over the past month, and was up more than 10 percent on the day alone on Monday, the futures pricing suggests investors reckon that the eye-watering price increases seen in bitcoin in recent months could be set to slow down.
Although there are hopes that the futures will draw in investors who would not previously have touched the market, most fund managers at larger asset managers and institutional investors still say bitcoin remains too volatile and lacks the fundamentals that give other assets value.
"There's no place for bitcoin in a multi-asset portfolio given the very high volatility," said Robeco Chief Investment Officer Lukas Daalder.
"We've looked at it in the past but if you look at the number of times that you need to trade to keep your exposure at the same level, after one week you need to rebalance the portfolio already," he added.
The two-month contract was trading at $17,910, a 9 percent premium over the spot price, while the three-month contract was changing hands at $18,080, a 10 percent premium.
Despite those being modest when compared with bitcoin's recent moves - a 270 percent increase over the past three months and a 230 percent rise in the last two months - they still showed a lack of appetite from investors to take large "short" positions betting against bitcoin.
"The premiums have so far been very high, demonstrating that few want to take the short side of the trade," said Altana Digital Currency Fund manager Alistair Milne, whose cryptocurrency fund has $35 million in assets under management.
Bitcoin is up more than 1,500 percent so far in 2017, having started the year at less than $1,000.
"MARCH TOWARDS LEGITIMISATION"
In just over 15 hours, 2,895 one-month contracts had been traded, meaning just over $51 million had been notionally invested. That compares with daily trading volumes of more than $20 billion across all cryptocurrencies, according to trade website Coinmarketcap.
Just 18 trades of the two-month contracts had been traded.
There had been speculation that the launch of Cboe's futures would trigger more gyrations in the market. But while volatile compared with traditional currencies or assets, bitcoin's 10 percent rise on Monday was nothing out of the ordinary for it.
Bitcoin surged more than 40 percent in 48 hours last week, before tumbling 20 percent in the following 10 hours.
"(Bitcoin futures) will speed up the march towards legitimisation of an asset class that only a few years ago many law enforcement agencies would have argued had limited legitimate reasons for people to use," said Jo Torode, a financial crime lawyer at Ropes & Gray in London.
The futures are cash-settled contracts, allowing investors exposure to bitcoin without actually having to hold any of the cryptocurrency.
The futures are based on the auction price of bitcoin in U.S. dollars on the Gemini Exchange, which is owned and operated by virtual currency entrepreneurs and brothers Cameron and Tyler Winklevoss.
While bitcoin's price rise mystifies many, its origins have been the subject of much speculation.
It was set up in 2008 by an individual or group calling themselves Satoshi Nakamoto, and was the first digital currency to successfully use cryptography to keep transactions secure and hidden, making traditional financial regulation difficult if not impossible.
Central bankers and critics of the cryptocurrency have been ringing the alarm bells over the surge in the price and other risks such as whether the opaque market can be used for money laundering.
"It looks remarkably like a bubble forming to me," the Reserve Bank of New Zealand's Acting Governor Grant Spencer said on Sunday.
"We've seen them in the past. Over the centuries we've seen bubbles and this appears to be a bit of a classic case."
Somebody who invested $1,000 in bitcoin at the start of 2013 and had never sold any of it would now be sitting on around $1.2 million.
Heightened excitement ahead of the launch of the futures has given an extra kick to the cryptocurrency's scorching run this year.
The CME Group is expected to launch its own futures contract on Dec. 17.
The launch has so far received a mixed reception from big U.S. banks and brokerages, though.
Several online brokerages, including Charles Schwab Corp and TD Ameritrade Holding Corp, did not allow trading of the new futures immediately.
The Financial Times reported on Friday that JPMorgan Chase & Co, Citigroup Inc would not immediately clear bitcoin trades for clients.
Goldman Sachs Group Inc said on Thursday it was planning to clear such trades for certain clients.
(Additional reporting by Chuck Mikolajczak and John McCrank in NEW YORK,; Michelle Chen in HONG KONG and Helen Reid in LONDON; Graphics by Ritvik Carvalho in LONDON and Reuters Graphics team; Editing by Lisa Von Ahn, Will Dunham and Keith Weir)