Here’s a look at some of the stocks the Yahoo Finance team will be watching for you today.

Apple (AAPL) is in focus after Fast Company reported that software problems with the next iPhone are creating a “sense of panic” among Apple engineers and designers. The reported bugs include issues with wireless charging and a 3D sensor for facial recognition. The report says the bugs may cause production and delivery delays for the 10th anniversary model, which may be called the iPhone 8.

Amazon (AMZN) remains in the spotlight this morning. The e-commerce giant said its third annual Prime Day event, which ended yesterday, is its biggest sales day in its history, growing 60% from last year. However, the company does not disclose sales numbers or Prime membership numbers. Amazon said its best selling product was the Echo Dot voice assistant.

We’re also keeping tabs on Twitter (TWTR). The social media site is welcoming a veteran investment banker to its C-Suite. Ned Segal will take over as the company’s chief financial officer. He is currently the senior vice president of Intuit and previously spent 17 years at Goldman Sachs. He will take over for chief operating officer Anthony Noto, who’s held the position for the last 8 months. Noto will remain Twitter’s COO.

Airline stocks are gaining altitude. Shares of American Airlines (AAL) and United Continental (UAL) are sharply higher in early trading after both airlines raised their second-quarter outlook for a key revenue metric, citing higher passenger miles. Delta Airlines (DAL) is set to report quarterly results on Thursday.

Walmart (WMT) is grabbing headlines this morning. Bloomberg is reporting that the retail giant plans to put more pressure on suppliers under a new program called “On-Time, In-Full.” The program requires suppliers to deliver fast-turning items, such as groceries and paper towels, on time or incur a penalty of 3% of their value. The new rules begin next month. Walmart believes this push will add $1 billion to revenue by making products more readily available in stores.