"So spare a thought for the companies scrabbling to jump off the bitcoin ship before it sinks. The currency’s value has been static for months (except for a brief boom and bust in early November when it was caught up in a Chinese ponzi scheme), but perhaps more damningly still, the hype has all but disappeared."

"I stand by my opinion that the Bitcoin is, in fact if not in intention, a fraud; it is an attempt to muscle-in on the enormous scam of universal fiat money, which is a curse upon mankind. And as a scam, it will go to the dust-bin of History, along with the world’s present fiat money system."

"Private currencies will fail to take off because there is no lender of last resort- there will always be boom and bust."

"This is my personal opinion, there will be no real, non-controlled currency in the world. There is no government that’s going to put up with it for long … there will be no currency that gets around government controls."

"“I’ll be surprised if bitcoin is here in five years,” he has told Fortune. “The value of bitcoin isn’t the currency, but the technology. I think once the world becomes more accustomed and attuned to the platform of bitcoin, the noise will go away, and the currency will go away too. The real transformation is the idea of taking all barriers down… Whatever currency or commodity you want to transact in, you can, and you can do it for free.”"

"“The main thing is that bitcoin network spends much more resources (electricity, hardware, human efforts) per transaction than current centralized systems,” Maclin wrote. “Bitcoin exists now, because of bubble-ponzi scheme.”"

"Fortunately, it’s unlikely that Bitcoin will survive long enough to generate the environmental disaster that would arise if it became a major part of the financial system. The same design feature that requires the use of so much electricity is the fatal flaw in Bitcoin as a currency."

"After analyzing the facts, it becomes apparent that Bitcoin is not destined to grow and mature beyond what it is today. Without a major overhaul of Bitcoin’s system and values, it is naïve to think that there will be widespread adoption. There are too many inherent problems and general complexities with the currency for it to gain mainstream traction."

"We have yet to see any meaningful adoption in the retail world and the institutional world seems quite lukewarm. . . . The deflationary quality of – by design and not by accident – is a major drawback. Deflation naturally encourages hoarding and delays spending, which is the behavior we are witnessing with BTC holders."

"Even in the unlikely event that it survives into the medium run, we would still rate its longer-term chance of survival as zero."

"In light of the above analysis, Bitcoin’s power usage per transaction isn’t remotely sustainable as a wholesale replacement for the conventional financial system. In the future, Bitcoin could massively gain popularity, pile on millions more transactions, and still be unsustainable due to the arms race between miners."

"It’s not clear what Bitcoin is or what it will be, but it is clear what it’s not. It’s not a currency. People don’t set prices in Bitcoin and, for the most part, don’t buy things with it either…. In the meantime, though, Bitcoin is still a little bit of a Ponzi—or is it a pyramid?—scheme that its libertarian early adopters are trying to cash in on."

"I don’t think Bitcoin is the correct technology to build these sorts of ideas on. I understand and strongly sympathize with the desire to move to decentralized systems and plan on eventually working in that space myself, but between Bitcoin’s efficiency problems and poor tolerance of network partitions, I do not think it’s suitable as a general purpose global decentralized database in the way people want to use it."

"Bitcoin, at its core, is an attempt to solve big socioeconomic problems through technology. But so long as it remains an overwhelmingly male domain, it’s going to continue to concentrate on the economic problems, while missing the big social problems. Which means that it’s going to continue going nowhere."

"“I’ll be surprised if bitcoin is here in five years,” he said. “It’s a means to an end. The value of bitcoin isn’t the currency, but the technology. I think once the world becomes more accustomed and attuned to the platform of bitcoin, the noise will go away, and the currency will go away too. The real transformation is the idea of taking all barriers down and having it be ubiquitous. Whatever currency or commodity you want to transact in, you can, and you can do it for free. That’s pretty revolutionary.”"

"The price of Bitcoin lost most of its value since its parabolic rise and speculators have lost a lot of money. The next electronic payment technology will be very large. We eagerly await the next version of electronic money to appear."

"Nevertheless, the chances of bitcoin, the most popular of this new breed of self-clearing financial instruments, making it as a mainstream currency are now zero. Prices have been floundering at around $350 a coin for months, escalating losses for those who invested at last year’s $1,200 highs. Add to this a stream of high-profile scandals over the past year, such as the collapse of Tokyo-based currency exchange Mt Gox in February, and you realise it is not a question of if but when the public loses interest in this experiment entirely."

"Bitcoin will fail, not for fans lack of trying, but rather its status will never be more than an interesting concept championed by those in the techie or libertarian camp. Holding Bitcoin is more of a political expression rather than a sound economic investment. . . . Ultimately, Bitcoin will be relegated to the history books unless structural changes are made. It will never be fully adopted in its current form, being nothing more than a neat concept for people to lose money on."

"“It’s not a currency now, it’s a pretend currency,” Robinson said. “It does not qualify or satisfy the requirements for a modern currency. The problem with disruptive technologies is that the disrupted has something to say about it. I say 10 years from now we will all have digital currencies – fiat currencies – and bitcoin will be remembered probably much like Pogs and Sinclair’s C5.”"

"One of the signs that Bitcoin is dying is that hardly anyone actually uses the currency. . . . The Bitcoin network is fading away and the price is destined to continue its downward march. This is likely to be the last year people take Bitcoin seriously (if last year wasn’t already). Whether Bitcoin disappears with a bang or a whimper, the end is coming."

"At this point, it’s merely a speculative commodity, just like tulip bulbs centuries ago or even Beanie Babies more recently. . . . Bitcoin has peaked and is very unlikely to escalate significantly in value again. . . . It’s basically an elaborate Ponzi scheme. . . . While I don’t relish anyone losing money, Bitcoin basically went out of the way to make itself vulnerable. For this reason, it is destined to fail."

"The Bitcoin is dead. Or is it? Well, not yet. But it will be very, very soon."

"Even if the price of Bitcoin doesn’t go to zero, the chances the Bitcoin community convincing the wider public, governments, and industry that Bitcoin really represents the future of the world’s digital economy will become extremely unlikely. . . . this grand technological experiment may have run its course."

"The virtual currency is looking increasingly beleaguered, and its price had been dropping steadily in recent months. . . . It is a reminder of the security issues that face any virtual currency seeking mainstream adoption, and it brings back memories of the infamous exchange Mt. Gox. . . . Combined with bitcoin’s reputation as an enabler for criminal activity, it is likely this public-image problem is hindering mainstream adoption. As one commenter on the discussion board Hacker News remarks, bitcoin is an “even worse” investment than gold."

"If Bitcoin were a currency, it’d be the worst-performing one in the world, worse even than the Russian ruble. But Bitcoin isn’t a currency. It’s a Ponzi scheme for redistributing wealth from one libertarian to another. . . . But in the long run, we’re all dead, and Bitcoin might be too."

"Even if the price of Bitcoin doesn’t go to zero, the chances the Bitcoin community convincing the wider public, governments, and industry that Bitcoin really represents the future of the world’s digital economy will become extremely unlikely."

"Bitcoins will go down in history as the most spectacular private Ponzi scheme in history. . . . The coins will never be the money of the future. . . . Bitcoins are too volatile in price ever to serve as a currency. . . . bitcoins are not money; dollars are money."

"We’ll sign off with the simple point that unless a massive amount of new capital is transferred into Bitcoin market sharpish — which is not impossible, since there are still a number of deep pocketed believers out there — it’s hard to imagine the asset class going any other way but south. Furthermore, it’s unlikely at this stage that either price rigging, mining cartels or lower energy costs will be able to reverse that trend."

"And that Bitcoin could only survive at the margins, where it would be isolated, and in no position to threaten Visa or Mastercard, or the underlying payment and messaging services that underpin the world financial system as it stands today. Then there’s The Oracle of Omaha who has one four letter word for bitcoin – joke."