LONDON, April 19 (Reuters) -

Bitcoin, the world's largest cryptocurrency, on Friday completed its "halving," a phenomenon that happens roughly every four years, according to according to CoinGecko, a cryptocurrency data and analysis company.

Bitcoin was fairly stable immediately afterward, falling 0.47% to $63,747.

Bitcoin enthusiasts had eagerly waited for the "halving" - a change to the cryptocurrency's underlying technology designed to cut the rate at which new bitcoins are created.

The halving was written into bitcoin's code at its inception by pseudonymous creator Satoshi Nakamoto as a way to reduce the rate at which bitcoins are created.

Chris Gannatti, global head of research at asset manager WisdomTree, which markets bitcoin exchange-traded funds, called the halving "one of the biggest events in crypto this year".

For some crypto fans, the halving will underscore bitcoin's value as an increasingly scarce commodity. Nakamoto capped bitcoin supply at 21 million tokens. But sceptics see it as little more than a technical change talked up by speculators to inflate the virtual currency's price.

The operation works by halving the rewards cryptocurrency miners receive for creating new tokens, making it more expensive for them to put new bitcoins into circulation.

It follows a surge in bitcoin's price to an all-time high of $73,803.25 in March, having spent much of 2023 slowly recovering from 2022's dramatic plunge. On Thursday the world's biggest cryptocurrency was trading at $63,800.

Bitcoin and other cryptocurrencies have been supported by excitement around the U.S. Securities and Exchange Commission's decision in January to approve spot bitcoin exchange-traded funds, as well as expectations that central banks will cut interest rates.

Previous halvings occurred in 2012, 2016 and 2020. Some crypto fans point to price rallies that followed them as a sign that bitcoin's next halving will boost its price, but many analysts are sceptical.

"We do not expect bitcoin price increases post halving as it has been already priced in," JP Morgan analysts wrote this week.

They expect bitcoin's price to fall after the halving, because it is "overbought" and venture capital funding for the crypto industry has been "subdued" this year.

Financial regulators have long warned that bitcoin is a high-risk asset, with limited real-world uses, although more have begun to approve bitcoin-linked trading products.

Andrew O'Neill, a crypto analyst at S&P Global, said he was "somewhat sceptical of the lessons that can be taken in terms of price prediction from previous halvings."

"It's only one factor in a multitude of factors that can drive price," he said.

Bitcoin has struggled for direction since March's record high and fallen in the last two weeks as geopolitical tensions and expectations that central banks will keep rates higher for longer unnerved global markets.

(Reporting by Elizabeth Howcroft, Kanjyik Ghosh and Urvi Dugar; Editing by Tommy Reggiori Wilkes, Toby Chopra and Cynthia Osterman)