There might not have been a drop in bitcoin, because the money has been flowing out of these other currencies into Bitcoin. It is considered more a "safe haven" in terms of crypto coin. So it might not necessarily be money leaving the crypto markets, just being reallocated to Bitcoin, etc.
Generally when you see spikes and gains as large as there have been in the past two months, it creates huge amounts of volatility. People exit positions to hold on to their profits, that were originally intended to be longer-term investments. Such large price movements in such short terms can have significant impacts, and create ripples that last longer than expected. At this point, prices are great if you have faith in the cryptocurrencies themselves.
Don't worry about what the crowd is doing...the crowd doesn't make money...the crowd is there to have money taken from them!