On The Fly: Top stock stories at midday

Stocks began the session in positive territory in anticipation of Janet Yellen's speech at the Jackson Hole Symposium. The initial reaction to the speech was that it was more hawkish than previous comments and the market dipped, but after digesting the comments the averages moved back to their highs. That only lasted to right before noon, however, as the market sold off near then and remains near session lows in early afternoon trading. ECONOMIC NEWS: In the U.S., second quarter GDP growth was revised down to a 1.1% rate from the 1.2% pace from the advance report. This compares to a 0.8% first quarter pace. The Michigan consumer sentiment reading for August came in at 89.8, below its last reading of 90.4. Wholesale inventories were unchanged in July. In her Jackson Hole speech this morning, Fed Chair Yellen said the case for a rate hike has "strengthened" in recent months. The economy is nearing its employment and inflation goals. She reiterated that policy is not on a pre-set course, however, and added that the Fed's ability to predict the rate path is quite limited. COMPANY NEWS: Shares of Herbalife (HLF) have dropped almost 6% after Pershing Square's Bill Ackman, who continues to hold a "very large" net short position in the stock, was interviewed on CNBC regarding The Wall Street Journal report that fellow billionaire investor Carl Icahn was recently in talks to sell his stake in the nutritional supplement maker, confirming many of the details of the Journal's report. Ackman said he was willing to buy a "few million" shares of Herbalife held by Icahn to facilitate his exit from a holding in the company, but added that he would have sold on "day one" had he bought the stock... Shares of Rackspace Hosting (RAX) gained over 4% to trade near $31.50 per share following the company's announcement that it had agreed to be acquired for $32 per share in cash by funds managed by affiliates of Apollo Global Management (APO). MAJOR MOVERS: Among the notable gainers was Bottomline Technologies (EPAY), which has advanced 12% after the company beat earnings and revenue expectations in the quarter. Also higher after earnings was Autodesk (ADSK), which gained over 6% following the company's "beat and raise" report. Research firms JPMorgan and Baird raised their price targets on the company's shares after the announcement. Among the noteworthy losers was Ulta Beauty (ULTA), which dropped over 5% despite the company posting its seventh straight quarter of double-digit sales growth and raising its full-year guidance. Deutsche Bank analyst Mike Baker said expectations for the retailer were "so high" that in-line to slightly better results probably aren't a "major positive catalyst." Also lower after quarterly results were GameStop (GME) and Brocade Communications (BRCD), which slipped almost 10% and 11.5%, respectively. Additionally, Big Lots (BIG) slid about 3% after the discount retailer announced that its sales declined slightly from last year and comparable store sales came in at the low end of its guidance. INDEXES: Near midday, the Dow was down 67.18, or 0.36%, to 18,381.23, the Nasdaq was down 8.56, or 0.16%, to 5,203.65, and the S&P 500 was down 5.39, or 0.25%, to 2,167.08.