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 other market-moving events.

Rumors of the Day: Google ( GOOG) is preparing to roll out its first attempt at selling ads within YouTube videos, according to reports in the Wall Street Journal and elsewhere. Reports say ads will show up at the bottom of the video screen and appear 15 seconds after the video starts. The ads will be displayed for 10 seconds.

Separately, Google launched Sky, a new feature for Google Earth that allows users to view and navigate through 100 million individual stars and 200 million galaxies. Google shares jumped $5.63 Wednesday afternoon, reaching $512.24.

Nymex Holdings ( NMX) on late Tuesday acknowledged that it had held takeover talks. "The company has talked to certain parties regarding a potential business combination," the company said in a statement. "Since discussions have been preliminary, there can be no assurance that the company will enter into any transaction; although the chairman indicated his belief that any transaction would have to be at a meaningful premium to the company's current share price." The stock surged $8.26 to $127.04 on Wednesday.

Today's Hot List: MGM Mirage ( MGM) and Dubai World have signed definitive agreements to form a long-term strategic relationship whereby Dubai World will invest about $5 billion in MGM, consisting of a $2.7 billion investment in CityCenter and up to $2.4 billion in MGM common stock. The companies will enter into a 50/50 joint venture in the landmark CityCenter development in Las Vegas, and Dubai World will acquire a significant minority equity position in the company. MGM is soaring $6.50, or 8.8%, to $80.82.

Tween Brands ( TWB) reports second-quarter earnings of 7 cents a share, vs. 15 cents a share predicted in a Thomson Financial poll of analysts. The company reported $213.7 million in revenue, vs. analysts' expectation of $211.87 million. Tween said that it is estimating earnings of between 40 cents and 45 cents per diluted share for the third quarter ending Nov. 3, below the 58 cents per diluted share reported for the year-ago period. Analysts had expected 68 cents a share. Tween plunged $10.85, or 28.1%, landing at $27.74.

Analyst Downgrades: Jeffries downgraded American Capital Strategies ( ACAS) to hold, from buy. The stock was sinking 44 cents to $40.28.

Analyst Upgrades: UBS upgraded Campbell Soup ( CPB) to buy, from neutral. The stock was gaining $1.12 to $37.07.

Latest Activist Situations: Daniel Loeb's Third Point disclosed a 9% stake in Bausch & Lomb ( BOL) in a regulatory filing after Tuesday's close. Bausch & Lomb is currently in a definitive merger agreement with Warburg Pincus to be acquired for $65 per share. Rival Advanced Medical Optics ( EYE) recently withdrew its $75-per-share offer for Bausch & Lomb. Bausch & Lomb shares gained 43 cents to $62.93 Wednesday.
Stockpickr is a wholly owned subsidiary of TheStreet.com.

If you liked this article you might like

George Soros' Top 10 Dividend Stock Picks for 2015

Top 10 New Stocks to Trade Like Hedge Fund Renaissance Technologies

4 Warren Buffett Dividend Stocks Jim Cramer Also Owns

6 Health Care Stocks John Paulson Is Betting On for 2015

11 Stocks Warren Buffett Loves for 2015: IBM, Wal-Mart and More