Investing in bitcoin is a risk, as the value can crash tomorrow.
I'm holding too so far, I believe in what bitcoin represents, so I'm taking the risk. Don't invest more than what you can afford to lose however, but if you can, you should buy more.
Also have a look in other cryptocurrencies.
not too risky, holding back means investing, waiting for the price to actually go up after it sells, doubled profits will await us, if indeed it will rise, if even down yes no problem as long as we hold it and wait for the price rise