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.
You're right. Everything has a risk when it comes to business. Just like as you said, Investing bitcoin is also a risk, so as holding. But holding is actually a good idea when you have so much patience that can make you earn more profits.