FSPTX, the 401k fund chosen by Surfer for my 401k plan, is similar. It went from ~$197 EOD Tuesday to ~$178 EOD Friday. I didn't see this drop in time to get out.
I will likely bail out of MU on Monday, but wait and see and hold FSPTX for a while longer. Watching/hoping for an end of year upturn before I make a move. If It drops further, I will get out.
FYI, my use of $USHL5 chart failed to see this move coming. Its is still rising from its low dip the week before Thanksgiving.
I spent time this past weekend trying to understand how to better diversify. Surfer is all about selecting one fund/stock from a group of twelve. I am now thinking I need to be holding more than one at any given time. Choosing which sectors, and selecting top in 3-5 of these sectors is my new focus.