Walmart and CVS ink a deal, American Express falls short, Apple partners with pharma giant

Here are the companies the Yahoo Finance team is watching for you today.

A new deal between Walmart and CVS. The retail giant signed a multi-year contract with CVS's pharmacy benefit program, Caremark. It comes days after CVS said Walmart was leaving their network, in a pricing dispute. Walmart is one of the nation's biggest pharmacy operators.

American Express is under pressure this morning after falling short in its latest earnings. Profits came in below expectations as expenses grew. That was driven in part by competition driving up costs. American Express has had to offer higher rewards for customers to keep them using its cards.

Apple is partnering with a pharma giant to see if its newest watches can detect heart problems. It's working with Johnson and Johnson to study a heart monitoring app on the Apple Watch. The J&J developed app can help detect irregular heart rhythms and the study will launch some time later this year.

Rio Tinto is expecting a further rise in exports in the year ahead. The miner said it shipped more iron ore from its Australian mining operations in 2018 than it did the prior year, about 2% more. This comes after it increased output from its newest mine and worked others even harder.

Tribune Publishing has a new CEO. The publishing company named Chicago newspaper executive Tim Knight CEO on Thursday, effective immediately. This comes after former CEO and chairman Justin Dearborn stepped down after nearly three years at the helm. The company also announced the departure of other top executives.