Well it depends on the amount of investment if you are looking to invest huge then you can invest into bitcoin but if have little to invest then obvious you have to go for promising alt coins like ETH or Litecoin and leave it for longer term as that's the only way to earn more profit with little investment rather than trading with little funds which has a greater risk of losing it
But looking at current bitcoin price I would rather prefer altcoins and try to buy it in bulk so that even if there is a slight price rise i can earn huge profit due to more shred in altcoins