The real test is whether even a small proportion of them can cash out without crashing the price.
This. There is so little money on exchanges now, so the money on exchanges has to increase at least 1000x
This exchange describes a real marketplace dynamic. However, a critical response to it illustrates some important points which most people overlook.
Firstly, given that the bitcoin appreciate, while the fiat depreciates, it would be very unwise for any of them to cash out, except in small part, as they require fiat to pay taxes or transact with atavistic counterparties.
Secondly, it matters not to the price of bitcoin whether all the holders cash out, so long as others take their place.
Thirdly, while the dynamic addressed in the quotes above plays an important role in the price of bitcoin, it is completely irrelevant to the value of bitcoin. The price is subject to sentiment, speculation, and imbalances of supply and demand, while the value of bitcoin derives from its monetary uses, and is described by Fisher's quantity theory of money: PQ = MV.
More interesting for society than the question of whether the price of bitcoin reaches $US2013 1mm, is the independent question of whether the monetary value of bitcoin will reach the equivalent of $US2013 1mm. While the former is very possible, I am skeptical of the latter because bitcoin is unlikely to displace all alternative monetary applications. Assuming 21mm bitcoin and a velocity of 6, the current global GDP priced in bitcoin implies a maximum value of about $US2013 320,000. Now it is possible that velocity will be less when currency has better wealth storage utility, and it is possible that maximum value will be reached long before M reaches 21mm, and it is possible that global GDP will grow significantly in the interim, and if the product of these sources of increase rises to about 3, that would suffice to imply a global capacity sufficient to raise the value of bitcoin to 1mm $US2013, however I doubt that bitcoin will ever replace more than half of all monetary applications. Even half requires a substantial stretch of the imagination.
In short, as a value investor, were bitcoin to rise to 1mm, I would definitely be a seller. In contrast, at 100k, I might still be a buyer, depending on the prospects for growth in use.
