The whole market including the big guys is driven by an underlying greed and fear psychology. It is the only explanation for how large established companies like ACI can gain and lose millions of dollars of market value in daily, weekly, monthly, etc. swings.
I have bought and sold several thousand shares at a time a half dozen times this year every time for a point or more profit per share.
My current holdings were purchased 5/6 at $30.71.
I think this decline is MM manipulation designed to get some big guys like GS in at a lower price. Though I do think the market was due for a pullback, again though because on "The Street" they know they have to create attractive entry points to drawn in money and allow their clients to make a profit.
Not sure why anybody even discusses upgrades and downgrades since they are B.S. If anything buy after downgrades and sell after upgrades, or best, totally ignore them.