"People buy into bitcoin in expectation of handsome returns. That expectation is sustained by the profits of those who cash out. But there is no external source of income. As in a classic Ponzi scheme old investors cashing out only do so at the expense of new money coming in. Unlike, say, investment in shares and bonds, bitcoin makes no contribution to the greater economic or public good."

"If I write about the inevitable obsolescence of Bitcoin, I'll have to lock my account again, won't I."

"In a crash, the holders of bitcoin will collectively have lost what they have paid the miners for their bitcoin. This sum may be not far from the sum originally invested with Madoff, after accounting for inflation. But bitcoin holders will have no one to pursue to recover this sum: it will simply have gone up in smoke, a social loss. The holders of bitcoin would then only wish it had been a Ponzi scheme."

"Some of the newer cryptocurrencies use blockchain technology far more efficiently than bitcoin does."

"Simple game theory tells us that a process of backward induction should, really, at some point, induce the smart money to get out. And were that to happen, investors really should be prepared to lose everything. Eventually."

"I am pretty sure Bitcoin and cryptocurrencies will continue to surprise us all, and that the greater fool is still to be found just around the corner. Cryptos have thrived because social media, the internet and connectivity have made it easy to disseminate the con around the global markets at incredible speed. They’ve succeeded because regulators haven’t stopped them – hat-tip to the Chinese for being ahead of the regulatory pack in that regard. Someday, the last greater fool will want his money back, and regulators will be exposed for not acting earlier."

"One thing I cannot understand is why the market (i.e. all the people speculating in cryptocurrency) does not yet recognize that there is no way that Bitcoin is going to be the winner of this technological race."

"In the absence of its use as a currency, though, the only thing supporting the value of crypto is the expectation that there’s always going to be someone else who’ll pay to take it off your hands. You’re betting, essentially, on being the last person holding the bomb before it goes off. With Squid coins, most people could see the wires sticking out and smell the cordite (let’s not even talk about the similarly ill-fated cryptocurrency Monkey Jizz). Bitcoin is heavy, shiny and attractive. But if you hold it right up to your ear, deep inside, I think you can hear something ticking."

"I personally think that Bitcoin is worthless."

"#Bitcoin’s volatility is its Achilles' heel and the reason it will never serve as a reliable unit of account or currency. Bitcoin is nothing more than a highly speculative asset with a fundamental value of ZERO."

"Many people believe that #Bitcoin is the "currency of the future." However, Bitcoin's volatility should punctuate the fact that it will NEVER be considered a currency. #BTC is just a highly speculative asset, and anyone who believes otherwise is living in fantasyland."

"The idea that #Bitcoin whales deliberately tank the market to shake out the little guys to get their coins is nonsense. The whales don't want the minnows to sell, they want them holding and hoping and buying the dip. The whales want out. They're fishing for dollars, not Bitcoin."

"And I would say that cryptocurrencies are a bubble. I would describe them as a limited supply of nothing. So to the extent there’s more demand than the limited supply, the price would go up. But to the extent the demand falls, then the price would go down. There’s no intrinsic value to any of the cryptocurrencies except that there’s a limited amount."

"Wildly volatile, highly speculative, and fundamentally worthless. #Bitcoin will NEVER be considered a currency. Are the #BTC evangelists and enthusiasts blindly digging their own graves?"

"I predict all these forms of cryptocurrencies that are not backed by central banks or backed by assets will ultimately go to zero. I can’t tell you when it will happen, but it’s inevitable that it will go to zero."

"Bitcoin investors seem to be relying on the greater fool theory — all you need to profit from an investment is to find someone willing to buy the asset at an even higher price."

"The BIS decision hopefully serves as a wake-up call for all of the happy bitcoin enthusiasts who actually believe that this penny arcade version of “money” could ever survive in a significant way in the government-centric world of money and banking."

"What just happened" Will be the most popular 3rd/4th quarter phrase of 2021."

"A few decades from now, Bitcoin and Ethereum will be collector items, not the currency of the global economy."

"So, what has bitcoin actually, you know, done? The answer, of course, is: basically nothing. And that’s why the world’s most-traded cryptocurrency is worth basically nothing."

"I don’t welcome a currency that’s so useful to kidnappers and extortionists and so forth, nor do I like just shuffling out of your extra billions of billions of dollars to somebody who just invented a new financial product out of thin air."

"So, there’s these things called nerds and in 2008 one of them we don’t know who because this person or group of persons is still anonymous made up Bitcoin out of thin air using the fake name ‘Satoshi Nakamoto’, which I think are the Japanese words for “monopoly money”."

"The cryptocurrency space today looks very similar to the internet space in 1997. In 1997, we thought Netscape Navigator was by far the most advanced sophisticated browser and there would never be anything to compete with that. And obviously here we are, Netscape is long [gone]."

"I realized it was not a currency without a government. It was just pure speculation. It’s just like a game ... I mean, you can create another game and call it a currency."

"Even if it does not amount to much in a practical sense, what Turkey’s move does represent is another nail in cryptocurrency’s coffin. Those nails have been hammered in at an accelerating pace; China has had a ban on Bitcoin trading in place since 2017, Nigeria banned cryptocurrencies in February this year, and India is preparing to impose what will be one of the world’s strictest bans on cryptocurrencies, including fines on those trading and holding assets."

"I don’t know where it will end or how it will end, but it will end. And when it ends, it will be ugly because there will be nothing there."

"Cryptocurrency is here to stay, but Bitcoin and its clones will be obsolete, probably within this decade. Once the fall starts, it will come hard and fast."

"Cryptocurrenies - A product of government malfeasance... These are false currencies, man made, another fiat. They have been given value by speculation caused be central bank unlimited printing & adoption of MMT... Government will have to kill them, just as India is doing. They’ll die"

"I think there is a good chance that over the next year the price of Bitcoin will drop towards its fundamental value, which is nothing... If Bitcoin were to lose half its present value — which is not unlikely, given its extremely volatile past behaviour — Tesla will lose around A$1 billion. As Elon Musk owns about a fifth of Tesla, he would then be down A$200 million. In contrast, I own no Bitcoin so I will lose nothing, which means I will have done A$200 million better than Musk."

"#BREAKING: another day, another record for #Bitcoin. Today, bitcoin broke $55,000/#BTC, which represents a 473% gain in the past 12 months. Remember, while the BTC bubble keeps growing, it’s fundamental value is zero."

"Bitcoin's current price is "unsustainable" unless the cryptocurrency's volatility dies down, according to JPMorgan."

"I've been getting rid of my BTC. Why? A currency is never supposed to be more volatile than what you buy & sell with it. You can't price goods in BTC. In that respect, it's a failure (at least for now)."

"Since the fundamental value of bitcoin is zero and would be negative if a proper carbon tax was applied to its massive polluting energy-hogging production, I predict that the current bubble will eventually end in another bust... Risky, volatile bitcoin doesn’t belong in the portfolios of serious institutional investors."

"Something with a long-term volatility of 80% can't be considered a medium of exchange. Just because everybody piles into an idea and talks it up doesn't mean it's a store of value."

"Bitcoin is nothing, it’s vapor, a concept of an idea. Transactions using bitcoin are few and far between. It’s not a store of value—anything that drops 30% in a week can’t play that role."

"Unlike governments, the closest Bitcoin gets to redistribution of wealth is celebrity-sponsored giveaways, which are at worst predatory hoaxes and at best promotional corporate stunts that offer $11 worth of cryptocurrency to people clearly desperate for far more. Help mine the stuff with a high-end computer and get the chance to heat your greenhouse as well."

"What is the future value of the dividend stream of Bitcoin? I can tell you that, that doesn’t take a prize winning mathematician. It is nil."

"Bitcoin’s recent 25% plunge illustrates why it will never be a true currency… The fact that Bitcoin has no intrinsic value (the way a stock or bond does) doesn’t mean it’s headed to zero. It just means that Bitcoin has become totally untethered from its original purpose. What was supposed to be a way to revolutionize people’s everyday financial lives is now mostly a way for people to get rich quick (or lose their shirts) or, in an ideal scenario, for people to protect their wealth against inflation. Bitcoin began as a cryptocurrency. It has ended as a cryptoasset."

"If you never sell your #Bitcoin, what difference does the price make? When it ultimately goes to zero, the percentage loss for all HODLers will be the same, 100%. The significant difference will be how much you pay, not the price. Those who “invest” the most will lose the most."