Bitcoin mining operations in the US and China are facing closures after the plummeting price of bitcoin means they may no longer be profitable.

The world's most valuable cryptocurrency is currently trading at around $4,500, having lost almost a third of its value in the space of a week.

Bitcoin mining – the process of generating new units of the cryptocurrency by solving complex puzzles – requires vast amounts of electricity to power the computers performing the calculations.

This means that the profitability of mining falls when bitcoin's price drops, and if the price falls too far then operations may no longer be economically viable.

Bitcoin's volatile history in pictures Show all 8 1 /8 Bitcoin's volatile history in pictures Bitcoin's volatile history in pictures Satoshi Nakamoto creates the first bitcoin block in 2009 On 3 January, 2009, the genesis block of bitcoin appeared. It came less than a year after the pseudonymous creator Satoshi Nakamoto detailed the cryptocurrency in a paper titled 'Bitcoin: A peer-to-Peer Electronic Cash System' Reuters Bitcoin's volatile history in pictures Bitcoin is used as a currency for the first time On 22 May, 2010, the first ever real-world bitcoin transaction took place. Lazlo Hanyecz bought two pizzas for 10,000 bitcoins – the equivalent of $90 million at today's prices Lazlo Hanyecz Bitcoin's volatile history in pictures Silk Road opens for business Bitcoin soon gained notoriety for its use on the dark web. The Silk Road marketplace, established in 2011, was the first of hundreds of sites to offer illegal drugs and services in exchange for bitcoin Bitcoin's volatile history in pictures The first bitcoin ATM appears On 29 October, 2013, the first ever bitcoin ATM was installed in a coffee shop in Vancouver, Canada. The machine allowed people to exchange bitcoins for cash REUTERS/Dimitris Michalakis Bitcoin's volatile history in pictures The fall of MtGox The world's biggest bitcoin exchange, MtGox, filed for bankruptcy in February 2014 after losing almost 750,000 of its customers bitcoins. At the time, this was around 7 per cent of all bitcoins and the market inevitably crashed Getty Images Bitcoin's volatile history in pictures Would the real Satoshi Nakamoto please stand up In 2015, Australian police raided the home of Craig Wright after the entrepreneur claimed he was Satoshi Nakamoto. He later rescinded the claim Getty Images Bitcoin's volatile history in pictures Bitcoin's big split On 1 August, 2017, an unresolvable dispute within the bitcoin community saw the network split. The fork of bitcoin's underlying blockchain technology spawned a new cryptocurrency: Bitcoin cash REUTERS Bitcoin's volatile history in pictures Bitcoin's price sky rockets Towards the end of 2017, the price of bitcoin surged to almost $20,000. This represented a 1,300 per cent increase from its price at the start of the year Reuters

The biggest casualty so far may be the US-based mining firm Giga Watt, which was forced to file for Chapter 11 bankruptcy this week after it was unable to pay debts of around $7 million.

"The corporation is insolvent and unable to pay its debts when due," the filing stated, according to CoinDesk.

"The corporation and its creditors would best be served by reorganisation of the corporation under Chapter 11 of the Bankruptcy Code."

Bitcoin has suffered two major price falls in less than a week, following months of market stability (CoinMarketCap)

The majority of bitcoin mining operations are based in China, where electricity costs are some of the lowest in the world.

Yet despite the cheap electricity, images and videos of mining operations shutting down in the country have been spreading across social media.

Hon Kong-based mining platform Suanlitou announced this week that it was unable to cover electricity fees for a 10-day period in November, according to the South China Morning Post.

Another group of Chinese cryptocurrency miners also reportedly shut down 20,000 mining rigs due to the fall in profitability.