i think so risky if you Holding bitcoin a long time , may be just 3-6 Month it's good . but , if you already got cheap or profit you should sell your bitcoin , and waiting dump again .
Its risky right but its good because your bitcoin will remain if you hold it for a long time. But if you want to make more money try to trade it to other type of coins here like altcoins so that it will grow and you can save more money.
Holding a coin is just risky if you don't know anything about the coin and you don't know what are the things that will happen in that coin in short, you don't have any information. Holding a coin can be risky also if you just hold it for short term and not long term because short term are very volatile to the price and you will get more chances to loss rather than to earn.