You can see articles about BTC in the media every day, world wide now.
This means it gains more and more popularity, more and more people will jump on the train and invest their money into BTC. it's time to move your altcoins / fiat to bullish BTC for nice profit.
Wait till the BTC run is over to buy cheap altcoin, but don't expect that it will be over soon ;)
In my opinion, good alts to look into after HODLing BTC are XMR, ETH, IOTA, EOS, NEO, OmiseGo, Power Ledger...
Enjoy :)
Something big is going to happen next month.
But I think there are some promising alt coin to hold on to.