Editor's Note: In this feature from Stockpickr, we highlight lists of stocks that have been upgraded by analysts or are experiencing activist situations or some other market moving events. Rumors of the Day: Rumors persist that Microsoft ( MSFT) could buy a large stake in the privately held social networking site Facebook. According to StreetInsider.com, there have been Internet rumors that Facebook founder Mark Zuckerberg was spotted in Seattle last week. Microsoft shares were gaining 25 cents to $29.71. IT consultant Acxiom ( ACXM) acknowledged its two private-equity buyers were backing out of a $2.25 billion buyout. Silver Lake and ValueAct Partners had agreed to buy the company for $27.10 in cash in May. The firms agreed to pay $65 million in cash as a break-up fee. The stock plunged $3.93, or 19.9%, to $15.85. Today's Hot List: Walgreen ( WAG) reported fourth-quarter earnings of 40 cents a share, below the consensus of 47 cents a share. The drug store had $13.4 billion in revenue, vs. the consensus of $13.55 billion. The company blamed lower generic drug reimbursements and higher salary, store and advertising expenses for the shortfalls. Walgreen was sinking $6.75, or 14.3%, to $40.48. Velcro Industries ( VELC) made a cash tender offer to buy back all outstanding shares of its common stock for $21 a share. The maker of hook and loop fasteners reserves the right to rescind the offer if it cannot buy all outstanding shares by Nov. 5, unless it extends the deadline. Shares were surging $2.83, or 15.8%, to $20.73. Analyst Downgrades: Deutsche Bank downgraded ConocoPhillips ( COP) to sell based on leverage to the weak refining industry as well as natural gas, which has been hurt by weak prices. The firm assigned an $80 price target. The stock fell 77 cents to $87. Analyst Upgrades: Wachovia upgraded the Chicago Mercantile Exchange ( CME) to outperform from neutral. The firm said the stock's valuation range should be between $650 and $665. Shares jumped $21.96, or 3.7%, to $609.31.