What market have you been watching where you think the statement 'Investing in bitcoin is extremely risky' has been proven wrong?
In one day in Nov 2017 bitcoin went up 15% in early trading then was down 21% later in the day before rebounding to close near even.
Whether bitcoin will be some like long lasting actual useful thing remains to be seen, but one thing that is undeniable is that investing in bitcoin is extremely risky.
This hold true just focusing on the general market behavior alone while ignoring all the issues such as getting money into and out of exchanges and hacks.
