Because nowadays any exponential growth is called a "bubble in forming". And because all stochastic exponential process eventually crash, or "underperform", it sounds really smart to "predict" a crash months or years in advance. Especially when using non-logarithmic axes, the predictions and the crash look really impressive.
You don't, however, often see these prophets of doom profiting from their predictions, because the exact timing of crashes isn't that easy at all.
Its actually generally a lot easier to profit buying a bubble than shorting it.There are a lot more points of increase than points of collapse.
Paulson made a fortune shorting the housing market,plenty of people predicted the collapse but Paulson picked the peak correctly.
The interesting thing is given his shocking trading performance since then he appears to have been lucky rather than smart.
Didier Sornette has some interesting theories(and dubious models) about bubbles,well worth a read.
Well, price has risen not because of businesses across the world adopting the currency but because of only Baidu saying they will accept Bitcoin. That does not justify 50% rise at all.
How do you know that that's why it's risen? Why does that not justify a 50% rise? Why does that imply the price will suddenly crash? Is this idle chat, or have you attempted to significantly short bitcoin somehow to take advantage of the financial gain from your certainty?
It's probably not just Baidu, but it definitely has something to do with chinese.
See this:
http://bitcoinity.org/markets/btcchina/CNY
(click 6 months and compare to USD) - the Chinese Yen volume was off the charts recently, and during the past day was approx. 40% of the USD's volume.
It seems as if Chinese began buying into Bitcoin.
You don't, however, often see these prophets of doom profiting from their predictions, because the exact timing of crashes isn't that easy at all.