While we have had a nice market for trading alt coins over nearly a month (see https://www.coinhills.com/statistics/volume-bitcoin-altcoin/), this nurturing environment may become choppier where people look to coins with more solid underlying fundamentals. I anticipate the turning point to be where Bitcoin breaks out above 18k to begin this trend reversal where attention is focused on Bitcoin again.
In the meantime, however, opportunities in alts persist and short surges in Bitcoin can provide valuable entries into other coins. They have been considerably strong since December. The "obvious" trade is when Bitcoin goes up alts go down - that was the major paradigm late last Summer into the Fall. Can a new trend develop where alt coin prices become uncorrelated with Bitcoin? Absolutely. That would definitely throw people off and is a future possibility you should keep in mind.
If you're interested in trading alts and don't yet have an account to do so, I recommend Binance (referral link that helps me a little while you still retain low (0.05% via BNB) fees: https://launchpad.binance.com/register.html?ref=10276631) and Bittrex (more alts, lately more sluggish though).