Looking at the current market trends it seems altcoin season might happen somewhere in mid-2020. I think the market is still recovering from the correction phase. First, we will see a BTC bull run followed by an alt bull run.
everything can be the other way. we can see first the growth of altcoins and only then the bull market of bitcoins and therefore the portfolio of each smart investor consists of bitcoin and altcoins
altcoin trend I think it still takes time, because at the moment bitcoin is dumping and is far enough down in price. I believe that when a bitcoin pump altcoin can follow it. we have to wait for the bitcoin trend to recover and we can only find altcoin trends