user21476: What on earth is driving the price of Bitcoin and other alternative currencies down lately? It's one thing for it to go down a bit but losing practically 80% of its value in less than a year? I feel like bitcoin is coming to a complete collapse. A list of the most important factors and a detailed explanation would be great guys. 

user3029: 
Bitcoin’s price has crashed. There is simply no other way to describe
  the -40% price decline that occurred in the first two weeks of 2015.
  It’s dismal, it’s disappointing and it’s a normal part of a free and
  open market. While Bitcoin is a transformative technology, it is not
  immune to the greed and fear that permeate every financial market.
Speculating on the true intentions of buyers and sellers in any market
  is a fool’s errand, but we can identify some catalysts. In this case,
  there appears to be three events that could be to blame for the price
  crash: BitStamp, CEX.io, and Russia.
BitStamp
BitStamp is one of the largest bitcoin exchanges and it was hacked
  last week. Before the exchange realized what was going on it lost over
  $5m in bitcoins to the hackers. To its credit, BitStamp shut down
  operations and made every investor whole before re-opening with vastly
  improved security.  Nonetheless, the blow to confidence in undeniable
  and its seems plausible that some investors were spooked and
  liquidated holdings.
CEX.IO
CEX is one of the largest mining operations in the world - it operates
  the GHash mining pool and sells mining contracts via the cloud - in
  the digital currency industry this is called ‘cloud mining’.  The
  recent price slump has made these mining contracts unprofitable and
  CEX has shut down these mining operations.  It’s likely that owners of
  these contracts have liquidated in favor of fiat currency - weighing
  on the price of bitcoin. Coindesk has an excellent post on the subject
  here.
Russia
Russia has threatened to make Bitcoin illegal for the better part of
  2014. However, it had not taken any action until recently.  This lack of action made bitcoin a hot investment as the Russian currency
  collapsed. Many speculated that wealthy Russians were using bitcoin as
  a way to withdraw money from Russia. In the last few days, Russia has
  begun to ban Bitcoin websites. For those interested in reading more,
  Engadget has a good post here.
Negative Feedback Loop
Unfortunately, these catalysts are conspiring to create negative
  feedback loop - the falling price is making more mining operations
  unprofitable, which in turn is resulting in more liquidation. This
  phenomenon is not unusual in markets and identifying these feedback
  loops can be quite profitable.  Until another catalyst forms and
  breaks the loop the price of bitcoin will remain depressed.  
I don’t know when or what will break the loop, but I do know that this
  will not be the last time it occurs.  There are few guarantees in
  financial markets, but I am sure that bitcoin will experience
  irrational bubbles, crashes and feed back loops (positive and
  negative). This fact has nothing to do with bitcoin the currency or
  technology; it has everything to do with human nature. 
Like any market, Bitcoin is an open natural system and is subject to
  the panic and euphoria that engulf all financial markets from time to
  time. It’s dismal, it’s depressing and…it’s normal.

Good explanation from here: http://briankellycap.tumblr.com/post/108083988817/why-bitcoins-price-has-crashed

user22914: 1) I don't know anyone actively uses Bitcoin, or other altcoin, that is not mining it and/or trying to profit from it. 
2) Bit coin price fluctuates, so as a business I would only use it to process a transaction and then convert it to cash ASAP.
3) Why is everyone losing Bitcoin in the news? True cash gets lost or stolen, but this make me fearful that my digital wallet could get lost or hacked. This may not be true, but it's how people feel. Losing money forever sounds bad, like I lit my cash on fire. 
4) The anonymity of Bitcoin makes it more susceptible to sensational scams and tax evasion which do not help in giving it credibility.
5) The concept and encryption process is incredible, what a great geeky hobby. I honestly don't know anyone that uses it other for fun or speculation. 
6) If the Warren Buffets of the world aren't on board, it makes it difficult.

“Stay away. Bitcoin is a mirage. It’s a method of transmitting money. It’s a very effective way of transmitting money and you can do it anonymously and all that. A check is a way of transmitting money, too. Are checks worth a whole lot of money just because they can transmit money? Are money orders? You can transmit money by money orders. People do it. I hope bitcoin becomes a better way of doing it, but you can replicate it a bunch of different ways and it will be. The idea that it has some huge intrinsic value is just a joke in my view.” - W.B


user5406: Adding to my answer on What are some of the proposed ideas to why the Bitcoin dropped to sub $400 in the end of summer 2014?, which I think is still mostly accurate:
Bitstamp loot
There are about 19k bitcoins held by the hacker that raided Bitstamp. While, as far as I know, they haven't found their way back into the market, it is an amount that would impact the markets if it were dumped. It is possible that some speculators were expecting a dump, and tried to position themselves to buy low. Such a dump in itself could have scared the already skittish market into further dumps.
Bitstamp has no trading fee until 19th
While Bitstamp seems to have weathered the hack well-enough, they are not taking any trading fee until the 19th. The fee usually being 0.2% – 0.5%, trades on much smaller movements are currently profitable. As Bitstamp is still the most important Western Exchange, this might have spiked a new dynamic.
The loss in value
Markets amplify the current trend. The loss in value is causing fear, leading to further dumps, creating a catch-22.
Russia banning Bitcoin websites
Bitcoin supposedly was a hip way to withdraw money out of Russia for a while. Although Russia had been rattling with their saber a while towards Bitcoin, they are finally starting to take action by blocking Bitcoin services there now. This might induce a trend of Russians moving out of Bitcoin.
Butterfly Labs has to sell their stash to confirm with financial obligations
Apparently, Butterfly labs has been ordered by court to refund their customers. According to rumors on reddit, they have been selling thousands of Bitcoins and are still sitting on more than 90k.
Mining operations sliding into unprofitable ranges
A bunch of mining operations, as for example CEX.IO, have cited that the current price makes their mining unprofitable. To cover financial obligations, they have to liquidate a larger percentage of their bitcoins than before, perhaps even their saved holding they were hoping to carry over to the next bubble. With the dropping price covering their obligations by liquidating bitcoins only gets more bitcoin-expensive.
Bringing oneself in position to buy takes a few days
When the price quickly lost value, few of those that were interested in catching up the cheap coins were already in position to buy. As it takes a few days for money to be transferred to exchanges, the buy reaction is a bit delayed in comparison to a price drop.
Especially on Bitstamp where deposits were closed for a few days during the slump in the aftermath of the hack, people were probably waiting for the dust to settle. In fact, a lot of the deposits from Bitstamp were immediately withdrawn on reopening. 
Once the dust settled, and people started to realize that Bitstamp actually appeared to be in good shape, it still took a few days for potential buyers to transfer money to Bitstamp, which would explain why the price was somewhat shifted lower on Bitstamp in comparison to other exchanges for a while.
As usual: I'm a computer scientist, not knowledgeable in economy beyond what I read here and there. Please do not consider this investment advice; I have been wrong before. Please trade responsibly.

21476: <p>What on earth is driving the price of Bitcoin and other alternative currencies down lately? It's one thing for it to go down a bit but losing practically 80% of its value in less than a year? I feel like bitcoin is coming to a complete collapse. A list of the most important factors and a detailed explanation would be great guys. </p>
 3029: <blockquote>
  <p>Bitcoin’s price has crashed. There is simply no other way to describe
  the -40% price decline that occurred in the first two weeks of 2015.
  It’s dismal, it’s disappointing and it’s a normal part of a free and
  open market. While Bitcoin is a transformative technology, it is not
  immune to the greed and fear that permeate every financial market.</p>
  
  <p>Speculating on the true intentions of buyers and sellers in any market
  is a fool’s errand, but we can identify some catalysts. In this case,
  there appears to be three events that could be to blame for the price
  crash: BitStamp, CEX.io, and Russia.</p>
  
  <p>BitStamp</p>
  
  <p>BitStamp is one of the largest bitcoin exchanges and it was hacked
  last week. Before the exchange realized what was going on it lost over
  $5m in bitcoins to the hackers. To its credit, BitStamp shut down
  operations and made every investor whole before re-opening with vastly
  improved security.  Nonetheless, the blow to confidence in undeniable
  and its seems plausible that some investors were spooked and
  liquidated holdings.</p>
  
  <p>CEX.IO</p>
  
  <p>CEX is one of the largest mining operations in the world - it operates
  the GHash mining pool and sells mining contracts via the cloud - in
  the digital currency industry this is called ‘cloud mining’.  The
  recent price slump has made these mining contracts unprofitable and
  CEX has shut down these mining operations.  It’s likely that owners of
  these contracts have liquidated in favor of fiat currency - weighing
  on the price of bitcoin. Coindesk has an excellent post on the subject
  here.</p>
  
  <p>Russia</p>
  
  <p>Russia has threatened to make Bitcoin illegal for the better part of
  2014. However, it had not taken any action until recently.  This lack of action made bitcoin a hot investment as the Russian currency
  collapsed. Many speculated that wealthy Russians were using bitcoin as
  a way to withdraw money from Russia. In the last few days, Russia has
  begun to ban Bitcoin websites. For those interested in reading more,
  Engadget has a good post here.</p>
  
  <p>Negative Feedback Loop</p>
  
  <p>Unfortunately, these catalysts are conspiring to create negative
  feedback loop - the falling price is making more mining operations
  unprofitable, which in turn is resulting in more liquidation. This
  phenomenon is not unusual in markets and identifying these feedback
  loops can be quite profitable.  Until another catalyst forms and
  breaks the loop the price of bitcoin will remain depressed.  </p>
  
  <p>I don’t know when or what will break the loop, but I do know that this
  will not be the last time it occurs.  There are few guarantees in
  financial markets, but I am sure that bitcoin will experience
  irrational bubbles, crashes and feed back loops (positive and
  negative). This fact has nothing to do with bitcoin the currency or
  technology; it has everything to do with human nature. </p>
  
  <p>Like any market, Bitcoin is an open natural system and is subject to
  the panic and euphoria that engulf all financial markets from time to
  time. It’s dismal, it’s depressing and…it’s normal.</p>
</blockquote>

<p>Good explanation from here: <a href="http://briankellycap.tumblr.com/post/108083988817/why-bitcoins-price-has-crashed" rel="nofollow">http://briankellycap.tumblr.com/post/108083988817/why-bitcoins-price-has-crashed</a></p>
 22914: <p>1) I don't know anyone actively uses Bitcoin, or other altcoin, that is not mining it and/or trying to profit from it. </p>

<p>2) Bit coin price fluctuates, so as a business I would only use it to process a transaction and then convert it to cash ASAP.</p>

<p>3) Why is everyone losing Bitcoin in the news? True cash gets lost or stolen, but this make me fearful that my digital wallet could get lost or hacked. This may not be true, but it's how people feel. Losing money forever sounds bad, like I lit my cash on fire. </p>

<p>4) The anonymity of Bitcoin makes it more susceptible to sensational scams and tax evasion which do not help in giving it credibility.</p>

<p>5) The concept and encryption process is incredible, what a great geeky hobby. I honestly don't know anyone that uses it other for fun or speculation. </p>

<p>6) If the Warren Buffets of the world aren't on board, it makes it difficult.</p>

<blockquote>
  <p>“Stay away. Bitcoin is a mirage. It’s a method of transmitting money. It’s a very effective way of transmitting money and you can do it anonymously and all that. A check is a way of transmitting money, too. Are checks worth a whole lot of money just because they can transmit money? Are money orders? You can transmit money by money orders. People do it. I hope bitcoin becomes a better way of doing it, but you can replicate it a bunch of different ways and it will be. The idea that it has some huge intrinsic value is just a joke in my view.” - W.B</p>
</blockquote>
 5406: <p>Adding to my answer on <a href="https://bitcoin.stackexchange.com/a/30733/5406">What are some of the proposed ideas to why the Bitcoin dropped to sub $400 in the end of summer 2014?</a>, which I think is still mostly accurate:</p>

<h2><strong>Bitstamp loot</strong></h2>

<p>There are about 19k bitcoins held by the hacker that raided Bitstamp. While, as far as I know, they haven't found their way back into the market, it is an amount that would impact the markets if it were dumped. It is possible that some speculators were expecting a dump, and tried to position themselves to buy low. Such a dump in itself could have scared the already skittish market into further dumps.</p>

<h2><strong>Bitstamp has no trading fee until 19th</strong></h2>

<p>While Bitstamp seems to have weathered the hack well-enough, they are not taking any trading fee until the 19th. The fee usually being 0.2% – 0.5%, trades on much smaller movements are currently profitable. As Bitstamp is still the most important Western Exchange, this might have spiked a new dynamic.</p>

<h2><strong>The loss in value</strong></h2>

<p>Markets amplify the current trend. The loss in value is causing fear, leading to further dumps, creating a catch-22.</p>

<h2><strong>Russia banning Bitcoin websites</strong></h2>

<p>Bitcoin supposedly was a hip way to withdraw money out of Russia for a while. Although Russia had been rattling with their saber a while towards Bitcoin, they are finally starting to take action by blocking Bitcoin services there now. This might induce a trend of Russians moving out of Bitcoin.</p>

<h2><strong>Butterfly Labs has to sell their stash to confirm with financial obligations</strong></h2>

<p>Apparently, Butterfly labs has been ordered by court to refund their customers. According to <a href="http://www.reddit.com/r/Bitcoin/comments/2sdwf8/butterfly_labs_is_the_culprit/" rel="nofollow noreferrer">rumors on reddit</a>, they have been selling thousands of Bitcoins and are still sitting on more than 90k.</p>

<h2><strong>Mining operations sliding into unprofitable ranges</strong></h2>

<p>A bunch of mining operations, as for example CEX.IO, have cited that the current price makes their mining unprofitable. To cover financial obligations, they have to liquidate a larger percentage of their bitcoins than before, perhaps even their saved holding they were hoping to carry over to the next bubble. With the dropping price covering their obligations by liquidating bitcoins only gets more bitcoin-expensive.</p>

<h2><strong>Bringing oneself in position to buy takes a few days</strong></h2>

<p>When the price quickly lost value, few of those that were interested in catching up the cheap coins were already in position to buy. As it takes a few days for money to be transferred to exchanges, the buy reaction is a bit delayed in comparison to a price drop.</p>

<p>Especially on Bitstamp where deposits were closed for a few days during the slump in the aftermath of the hack, people were probably waiting for the dust to settle. In fact, a lot of the deposits from Bitstamp were immediately withdrawn on reopening. </p>

<p>Once the dust settled, and people started to realize that Bitstamp actually appeared to be in good shape, it still took a few days for potential buyers to transfer money to Bitstamp, which would explain why the price was somewhat shifted lower on Bitstamp in comparison to other exchanges for a while.</p>

<p><strong><em>As usual: I'm a computer scientist, not knowledgeable in economy beyond what I read here and there. Please do not consider this investment advice; <a href="https://bitcoin.stackexchange.com/a/22520/5406">I have been wrong before</a>. Please trade responsibly.</em></strong></p>
