we can say that because not entire altcoin got pump, so we just say it with silent bull run, and i think this is the right time for invest more before facing the real bull upward.
I think this silent bull run is what some of us refers to as Semi bull run which I also believe that is the stage we are now, because I am not expecting the full bull run, which is usually when most altcoins head to their peak too.
One thing I have studied in the past which I dont know if it will be applicable to this time bull run is that Bitcoin has its own bull run separately while altcoins has its own too separately, because the time I made so much out of altcoins last time was the period bitcoin was going sideways and not when bitcoin hit bull run. So I think the altcoins bull run is still quite far while bitcoin full bull will happen very soon.