Throughout its short crypto history, Bitcoin has always been a safe investment, especially in the long run - so most will advise you to direct your investment in that direction. Of course if your goal is to profit in the short term, another option is to invest in some of the altcoins that tend to give you a higher profit compared to Bitcoin.
I'm not going to tell you which altcoin to invest in, I think the financial responsibility is on each of us individually - but I can advise you not to invest all your money in one coin, reduce your risk and invest in more of them that you think will end this year with at least 100% growth.
Of course, there are various speculations that BTC will be worth at least $100 000 by the end of the year, and some are speculating about as much as $300 000. I suggest you visit CMC, look at the top 20 or even 50 coins and their history in at least the last 6 months, it can give you some guidance in what to invest your money in