I think that investing in everything is risky especially bitcoin. Dont take anyones advice about what will happen with the currency. Personally I believe we are just starting, just my own opinion and you shouldnt consider that as investment advice as well.
I think Never invest more than you are able to lose Bitcoin is a very risky investment and you should keep in that in mind at all times. especially the price Bitcoin is still going down this time.
You already have your answer! Well anyway I wish to add that you need to watch the market and play accordingly. Already the value of BTC came to a little less than 6000$ which was a great time to buy. Similarly if we find such a slump in the value in this year again, which might be unlikely, you can buy again.
There are many points to consider prior to an investment. How many BTC are you going to invest in? Is there any specific need based investment? Or you want to simply make good profits by the end of this year?
I would certainly say that if you plan to invest now and sell in the end of the year then you can make a few thousand dollars' profit. But in such a case, you can as well try investing in some Altcoins as well where the profit margin can come much earlier. You may end up making more profits with Altcoins when you carefully observe the markets. When the price is in the ascendance, I would advise you to rather invest in Altcoins and wait a little for prices to fall in BTC.
If it is an investment to meet a need, then when you gain the required value, you must sell. And when you can afford, reinvest. And if the investment is for long term gains then you must simply forget after investing for a few years. That will reap you enormous profits.