Granted, I haven't been watching prices long, but it SEEMS that Bitcoins aren't any riskier than normal stock. Maybe they'll go back up to $20 each, maybe they'll drop down to $0.01 per BTC, but regular stock carries the same sort of risk.
Be nice if it was more stable, true, but I don't think it's much riskier than any other sort of investment. Just keep your computer safe from being hacked.
Aren't stocks less volatile? I mean, last week Bitcoin price dropped 20% in one day.
Not really. It happens. A lot of stocks are relatively stable (Walmart, IBM, Apple; I think), but the majority can trade pretty wildly, depending on number of shares and whether the brokers had salmon or chicken for lunch. That's how day traders make tons of money.