With the recent changes in BTC price, altcoin is getting weaker against BTC, so, this is a good time to pick and fill the bag. Another important part is, after BTC bullrun, once BTC get stable, altcoin follow the bullish trend.
Is it right decision to pick some more altcoin?
yes, with lower BTC prices, most of the other altcoins will be followed, because the price of BTC is very influential in the market. with this decline it can be utilized as best as possible to start investing in the expected altcoin because of its affordable price. make sure the altcoin to be invested has a good development later by analyzing it first so you don't regret it later.