Hello. Note that there are only few stable altcoins when btc is increasing. Those altcoins are already established and the progress are keep going, if you choose to invest in alts, then choose them. Anyways, most of the time as the btc increases the value of alts are going opposite ways but no worries, altcoins will gonna regain their spot, specially if they are really promising projects.
You made a very good point. One of the best things to do is to research a few coins. Pen down about 5 and watch their prices.
As you said, AltCoins often go in opposite direction of BTC, so one should wait for BTC to go up, and buy the selected coins especially the ones that are going down.
The key here is volume, AltCoins are often sold in cents so, to make tangible profits if you're trading, buy a good volume. Factor in your transaction fees for buying and possible selling, if you won't be holding for long.
