buying or holding a bitcoin is also a investment and also it has a risk because you spend and risk money just to make some profit and try if your money will grow . you should think twice before investing your money .
I think all investing is risky, but the good thing with bitcoins is that the price fluctuates that much and we have reach the peak of $1,000 and with that amount we can still achieve so it is good to buy now and hold it in the future.
Yes, earlier I made some investments and hence lost my bitcoins by 25% but now due to the price increase I again have 175% ( as the price has been doubled ) . So, yes I vote for holding right now better than investing. Still, investing will get you chances to raise the number of holding bitcoins.