halving expectation is there, and btc price may keep in a rational range for a time before it explodes.
so maybe it is good time to buy alts to get more btc now?
So far, it's somehow good to buy altcoins but only consider buying the top-altcoins in the market. And for now, it's better to buy bitcoin. I have seen the rapid increase of bitcoin in the past few days and it somehow attracts attention because we expected that after this halving we will see new bullish on the price. Probably right now, we should watch the movement of the market because we don't know what will happen after the halving of bitcoin and we don't know if there will be a sudden drop/crash, so once it happens we can instantly filled our bags.
But if you really intend to get more bitcoin, why not buy bitcoin in the first place? And it's a better option to buy more investment in bitcoin than other altcoins. And lastly, what I think OP wants to tell is that when you buy altcoins at a lower price and sold it at a higher price, you will earn a huge profit especially when it is paired with bitcoin wherein you will bitcoin may increase.