For the first time, when I move to cryptocurrency world (March 2016) the btc price were around $400... it was risen up to $17000 few days ago... 17000/400 x 100 = it's 4520% growth in 21 months.
There's a popular statement such as, the thing what it is existing next to the risk is the success.
Should I believe it and do what I didn't do 21 months ago?
No one can really know whether it's a good or bad idea to believe it but historically, Bitcoin will continued to rise every time it's dipped
So it's best to ask yourself , are you sure It will continue?