If you want to track how altcoins are likely to perform relative to $BTC, one of the main factors will be the $ETH/BTC chart strength.
After the recent squeeze, it has been consolidating between this ~0.022-0.026 range.
If it were to break above that, it should temporarily give another boost to ALT/BTC pairs and primarily ETH related coins (DeFi, ETH Memes, L2s etc).
Below that 0.0224 horizontal I'd start getting very cautious on alts relative to BTC as that might mean this will retrace the squeeze from before. Keep in mind, it does not mean USD values have to go up or down based on this. We often see BTC rally hard and ALT/BTC pairs to drop as was the case for most of this cycle. The opposite can also occur.