For daily trading, I also choose altcoins, because we can get higher profits. This is in my opinion. I only hold bitcoin for the long term, and choose the top 20 coins for daily trading. I will analyze the coins that I will use for daily trading, before I decide to buy.
If not that Bitcoin volatility seems to have reduced and the halving has came and gone, Bitcoin is a very good coin to trade because you can always make good profit even if you are a daily trader and altcoin are super active but the downside is what I don't like, when they want to fall, they fall like they are about die.
I'm addition, don't only hold Bitcoin, Ethereum is a good coin to hold, the price we are seeing right now used to be what Bitcoin was called last few years ago but see what Bitcoin has done, don't be surprised if Ethereum get the same hype and run.