Putting your money in the bank wont gain you anything. Thus if you want to maximize your chance to grow it, investing is the good option. But the problem is the money that you will going to use is not a spare money since you're assuming there's a guaranteed profit by next year.

Price of bitcoin is unpredictable, if you're willing to take risk then timing when to buy and that is during dip, then hold. If the price plunged you will only lose the value but not the number of your bitcoin, the only solution is to be patient and hold even it takes long period.

Take risk but have less expectation.