If you think you will do investment and trading together then that is totally up to you which needs good amount of financial support. If there is good financial support you can invest in any one coin for a long time and carry out your own trading activities in all other coins.
I think this should be the best thing to do because depending on just one source of income isn't always safe. If we can do both trading and investing. It'll benefits us because when you trade and make profits, you can reserve some profits and use them to invest into Bitcoin or other altcoins that you're interested in although it'll be better we Invest in Bitcoin because that's the most safest cryptocurrency you can invest in and be sure you can make profits in the bull market.
Trading needs your active awareness because you'll have to be active with what's happening in the market to make your trading very profitable but investing doesn't need you to be very active in the market as you can just buy and hold and wait for the bull market, so both are combinable.