BRK.B has followed the market higher since Feb 11th, I am setting alerts early. We will see if the market correction since the beginning of 2016 was only a dip to be bought, or an early warning sign of a bearish trend unfolding in the months to come. Similar health checks can be done with SPY:IWM, COPX, FDX, TLT, HYG, FXY, UVXY.......