Crazy or not there are still peopled investing even if the price is at the peak, I really think this is not the end of the increase of the price of bitcoin, and there are so much for us to go in a wide variety of value, and in my opinion if the last block isn't mined yet there is a possibility that the price would still increase.
Right,maybe they were not aware that bitcoins value is unpredictable it can soar anytime.Those capitalist take risk and still invest in its highest value,its what they want to take chances and stay positive that it will continue to rise and would might surpass to $20k or even more.