I too have the feeling that this is the peak but when I think about why, I don't have any reason other than this is the highest price to date. With a relatively small total valuation you're susceptible high volatility. Bitcoin has had lots of peaks and valleys but over its brief history. But, the peaks have always been higher than the valleys. Is there any reason to suspect this trend to stop? I think the underlying driving force for the overall increae in valuation is the adoption of bitcoin as currency. As far as I can tell, this is increasing pretty rapidly and will most likely continue increaseing.