The Options Scan picked up heavy MU Call activity on 8/1/2013 (yesterday). Notice in the Options Scan display below the 102810 calls versus the 9227 puts on the near strikes.
Switching to Yahoo, we can verify the heavy call presence for MU.
Based upon the chart and the stock action today, it looks like the Calls were sold for the premium, which means the seller feels the top is in for August in MU. One can see the clear price channel and diminishing MACD for MU.