Bitcoin and any other cryptocurrency may fail unexpectedly for reasons we don't know. That said, cryptocurrencies as a whole have shown positive trends and have reaffirmed my confidence time and time again. Like you said in your article the posibility to take $4,600 invested to make $25k is in my opinion worth it. I cannot be sure that the $4,600 won't incur a loss, but I am willing to take that chance.