Personally, I'd go for both (although, I'm not that strong in Bitcoin), I think I'd want short-term investments in Altcoins, and then long-term investments in Bitcoin.
Good, applying short term in altcoins investment is a good idea dat will make you to experience good side of d short term investment because dat is were new investors use to get more skills to improve in profit making in the community. Applying long term in BTC investment is a good plan dat will help you to increase higher financially when the price go higher than d current price in d market. I believe u no say e no easy to hold BTC long like 4 or 5 years, but if u can hold like dat years, u will have a good experience to share with people in dis platform.