After the big plunge over the past month, bullish investors knew it was just a matter of time before stocks bounced back. Today, the market delivered big gains, with most news sources pointing to the European Central Bank as the catalyst for the jump. Refusing to bow to pressure to stimulate Europe's economy, the ECB left interest rates unchanged. But sentiment in the U.S. is very different, as a Fed Open Market Committee member said that extending the Fed's Operation Twist is still on the table. With a whiff of stimulus in the air, the Dow Jones Industrials (INDEX: ^DJI) launched upward almost 170 points just before 11 a.m. EDT. The Nasdaq Composite (INDEX: ^IXIC) rose even more strongly, jumping nearly 2%. All 30 stocks in the Dow were up.

Intel (Nasdaq: INTC) was up more than 2% despite a report showing a year-over-year drop in worldwide semiconductor sales. The measure posted a 3.4% rise from the previous month, however, with some signs of strength in Asia, the Americas, and even Europe.

AT&T (NYSE: T) was one of the stocks posting the smallest gains. A Wall Street Journal article last night highlighted the challenge that the wireless carrier is having with customers choosing calling plans with fewer minutes for smartphones. With a trend toward data and away from voice, smartphones are less about phones and more about computing features like apps. AT&T needs to navigate those trends if it doesn't want to lose revenue.

Johnson & Johnson (NYSE: JNJ) also traded about flat as it announced that it would stop selling a surgical mesh product that has reportedly caused injury and even death. The problem is just the latest example of a troubling trend that has plagued J&J for years, with a huge number of recalls and other problems calling the company's quality control into question.

Stop worrying about Europe
Europe may not be fixed yet, but some companies in the U.S. are ready for whatever happens next on the troubled continent. Find out which stocks our experts are the most bullish on in the Fool's special free report: "3 American Companies Set to Dominate the World." Just click right here to get your free copy now.