On The Fly: Top stock stories for Monday

Stocks opened higher, adding to the records recently set by the major averages. While the Dow was able to hold onto most of its early gains, the S&P and Nasdaq dipped in the afternoon but still closed out with small advances. The news flow was fairly quiet as the biggest events expected this week, the rate decisions due from the Federal Reserve and the Bank of Japan, are still ahead. ECONOMIC EVENTS: In the U.S., the NAHB homebuilder sentiment index for September fell to 64, missing expectations for a reading of 67. COMPANY NEWS: About two weeks after United Technologies (UTX) announced an agreement to acquire Rockwell Collins (COL) in a big deal in the Aerospace and Defense sector, another nearly $10B deal was inked in the space as Northrop Grumman (NOC) agreed to buy Orbital ATK (OA) for approximately $7.8B in cash, plus the assumption of $1.4B in net debt. Orbital shares jumped 20% to close at $132.25 following the announcement, while Northrop added 3.4% as investors seemed pleased in their initial take on the deal... Shares of Ubiquiti Networks (UBNT) dropped nearly 8% to $50.62 after Andrew Left of Citron Research called the company a "total fraud" in a new report. Ubiquiti CEO Robert Pera took to Twitter in the afternoon to answer questions about his company. Scott Wapner of CNBC asked Pera via Twitter, "1. Left says your numbers 'are a farce' What's your response? 2. Why are there only four people on the board? 3. Why doesn't co have a CFO?" In a series of tweets, Pera responded with, "1. Ask KPMG (our auditors). Also, we have bought back $100mm's in stock...where did that cash come from? Not the tooth fairy...2. Why does Buffet only have ~20 people in his office?...3. CFO's self interest are in pleasing Wall St. to prop up their stock options and setup their next job...We have a CAO focused on accounting." MAJOR MOVERS: Among the notable gainers was Silver Spring Networks (SSNI), which jumped 24% to $16.10 after the company agreed to be acquired by Itron (ITRI) for approximately $830M net of cash, or $16.25 per share, a premium of 25% to Silver Spring's closing share price on Sept. 15. Also higher was Cohu (COHU), which gained 16% after Needham analyst Y. Edwin Mok upgraded the stock to Buy from Hold, citing the company's exposure to the growing auto infotainment space. Among the noteworthy losers was Super Micro Computer (SMCI), which dropped 9% after DA Davidson analyst Mark Kelleher downgraded the stock to Neutral, saying the company's delay in filing last year's 10K creates too much uncertainty. Also lower was Mattel (MAT), which fell 6% following media reports that retailer Toys 'R Us could file could file for bankruptcy as soon as today. INDEXES: The Dow rose 63.01, or 0.28%, to 22,331.35, the Nasdaq gained 6.17, or 0.1%, to 6,454.64, and the S&P 500 advanced 3.64, or 0.15%, to 2,503.87.