Well it is a gamble because you din't know if BTC will be at $100 next month or $200 or $40 or $20. Some people think it could never go back to $20 but it is very possible. But if you buy and it starts to tank on you, just sell before it gets too bad, just like with the stock market.
That's how the market crashes, everyone panic sells and then it drops.
Regards,
Martin.