Wal-Mart in China, and Microsoft techies — 5 things to know today by Laura Lorenzetti @FortuneMagazine April 29, 2015, 6:26 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Hello friends and Fortune readers. Wall Street stock futures are mixed to lower this morning, as quarterly earnings report season continues. Companies reporting today include Time Warner TWX and Mondelez International MDLZ before the opening bell, and Valeant Pharmaceuticals VRX.TO follows after the close. Cost cutting and an improving European car market helped Volkswagen beat first-quarter profit forecasts Wednesday, easing the pressure on management following the shock ouster of long-standing chairman Ferdinand Piech. Today’s must-read story is by Fortune’s Polina Marinova: Which presidential candidate is winning the Twitter vote? Four senators have officially announced their candidacy, and Fortune takes a look at who’s leading in the social media poll-scape. Here’s what else you need to know about today: 1. Wal-Mart WMT is betting big on China. The world’s biggest retailer plans to expand its footprint in China by nearly a third by opening 115 new stores by 2017, chief executive Doug McMillon said, in a renewed push to lure China’s grocery shoppers despite slowing growth. 2. Microsoft hosts its annual developer conference. Microsoft MSFT opens the doors to its most important event of the year today in San Francisco. The tech giant has been gearing up for big changes and is expected to announce the release date of its much-anticipated Windows 10 operating system. The OS is a return to basics for Microsoft, bringing back the Start Menu and a more PC-friendly version of the system. It will depend heavily on connecting its Office suite with its Azure cloud to transform the future of its applications. 3. Mastercard hit by strong U.S. dollar. Mastercard MA , the world’s second-largest debit and credit card company, reports its first quarter earnings before the market open. It is likely to report a fall in revenue due to a surging U.S. dollar. Mastercard gets nearly 60% of its payment volumes from outside of the U.S. And to add to the credit card company’s woes, analysts anticipate that Americans put less on their debit and charge cards in recent months due to low gas prices. 4. U.S. data deluge. The U.S. Bureau of Economic Analysis releases its preliminary estimate for first quarter growth at 8:30 a.m. ET. Gross domestic product is the main indicator of economic growth, and economists polled by Reuters expect it to reveal a 1.0% annual expansion rate. That’s a sharp slowdown from the fourth quarter last year when GDP expanded at an annual rate of 2.2%. The drag is likely due to a colder-than-usual winter and a strong dollar. A rebound is expected in the second quarter. The National Association of Realtors will report pending home sales at 10 a.m. ET, which are expected to be up 1.0% in March after growing 3.1% in February. 5. The Fed releases its statement. The Federal Open Markets Committee closes out its two-day meeting on interest rate policy today and will release its post-meeting statement at 2 p.m. ET. Not much is expected to go down in this meeting since the FOMC already ruled out an April rate hike, but investors will be looking for more information on exactly when they might start boosting interest rates. It could be as soon as June. Look out for any word on how comfortable the Fed is getting with inflation data.