The biggest week of earnings season is coming. Here are the 8 companies to watch - and what to look out for.

Visa hasn't missed analyst earnings-per-share estimates since the fourth quarter of 2015, and its stock has outperformed the S&P 500, Dow Jones Industrial Index, and Nasdaq Composite year-to date. Of the 39 analysts covering the stock, only one rates it "sell," according to Bloomberg data.

When Visa announces its quarterly earnings on July 23, watch for purchase-volume growth, an indicator that hints at whether consumers are spending more and keeping the economy healthy.

The company may also give updates on its recently-launched B2B Connect platform, which is meant to serve business-to-business payments without relying on credit or debit cards.

Finally, Visa acquired a few service companies in June, so the report may shed light on how these added businesses may boost revenue in the future.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $5.70 billion, versus $5.24 billion in the same period last year
• Earnings per share: estimated $1.31, versus $1.20 in the same period last year

Wall Street already expects a year-over-year drop for Boeing, largely due to grounding all of its 737 Max aircraft after two fatal crashes in the span of five months.

The company faces government scrutiny, several lawsuits and calls for compensation from airlines as fallout from the groundings continues. The plane manufacturer also delivered 150 fewer aircraft than its main competitor Airbus over the first six months of the year.

Boeing has seen no shortage of bad news in 2019, but hope is not lost for its second-quarter earnings. It's possible that the stock decline from the 737 controversy has already been priced in, as Boeing hasn't recovered from the early March peaks it reached before the crashes.

Pay attention to the company's cash flow and earnings per share to see if its still in the throes of recovering or if its finances are on the way back.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $20.47 billion, versus $24.26 billion in the same period last year
• Earnings per share: estimated $1.91, versus $3.33 in the same period last year

Facebook's second-quarter earnings report in 2018 didn't go too well — it lost over $120 billion in market cap the following day, marking the biggest disaster in US stock market history.

The social media giant has mostly recovered since then, but faces new hurdles in the form of government antitrust concerns, controversy around its proposed cryptocurrency and slowed advertising revenue.

Be sure to monitor for more news on its Libra cryptocoin project. Details on how it'll generate revenue for the company are scarce but if it's released in 2020 as expected, it could be Facebook's next cash cow.

Investors are also curious as to whether Facebook can maintain growth in digital advertising revenue as competing ad services from Amazon and Google pose a threat.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $16.50 billion, versus $13.23 billion in the same period last year
• Earnings per share: estimated $1.88, versus $1.74 in the same period last year

With a merger between Sprint and T-Mobile on the horizon, AT&T is likely to face new levels of competition in the telecom space. The company's shares have fallen after its last five earnings reports, but the impending 5G rollout and a new deal with IBM may give AT&T a healthy leg-up.

Look for updates on the company's progress on the 5G front, as well as its ability to recover from a brutal decline in video subscribers from its last quarter. Its recently unveiled HBO Max streaming service is set to launch next spring and host the popular offering "Friends" after Netflix loses its license. Netflix also disappointed with its recent earnings report, leaving plenty of space for HBO Max to catch up.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $44.74 billion, versus $38.99 billion in the same period last year
• Earnings per share: estimated $0.89, versus $0.91 in the same period last year

Google's parent company Alphabet has underperformed other FAANG portfolio members — Facebook, Amazon, Apple, and Netflix — and the S&P 500 in 2019. It announces earnings July 25 amid fears of an antitrust investigation against the company and political controversy surrounding YouTube's handling of "hateful" content.

Alphabet reported weaker-than-expected revenue growth in the first quarter, so analysts will likely pay close attention to whether the trend continues or the company finds a new way to boost income.

Google's ad revenue growth also trailed in the previous quarter, falling from 24% to 15% over the year. Missing this target again could spell danger for the company's short term investor interest.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $31.09 billion, versus $26.24 billion in the same period last year
• Earnings per share: estimated $11.15, versus $10.58 in the same period last year

Coming off the heels of the largest, and longest, Prime Day promotion in history, Amazon stock has nearly returned to record price it hit in early September 2018.

The ecommerce giant announces its second-quarter earnings July 25 and investors should look out for revenue coming from its Amazon Web Services business and whether its popular one-day shipping option has weakened profit margins.

AWS sales increased 41% year-over-year last quarter and represent one of fastest growing revenue streams for the company. Amazon has leaned more on this service as profit growth from its online retail business has slowed, so watch to see if AWS continues to grow rapidly or begins to stagnate.

Look out for questions regarding workplace health and safety during the earnings call as well. Thousands of employees went on strike during Prime Day in an effort to improve the company's warehouse conditions.

E-commerce operations have brought in fewer profits for the company in recent years, and greater expenses in the sector would bite into earnings even more.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $62.42 billion, versus $52.89 billion in the same period last year
• Earnings per share: estimated $5.58, versus $5.07 in the same period last year

Coasting off a recent all-time high, Starbucks needs to prove its stable revenue growth and thriving rewards program haven't slowed after beating estimates in its fiscal second quarter.

The rewards program recently launched in China, and since CEO Kevin Johnson announced in a previous earnings call that the company hopes to bring mobile order and pay to the country by the end of the year, expect more updates on performance in the region.

Starbucks' comparable-store sales — sales of stores open for more than 13 months and excluding foreign currency volatility — rose 3% globally last quarter. With management's guidance for the metric ranging between 3% and 4%, investors are looking to see if the July 25 report shows sustainable global sales growth.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $6.66 billion, versus $6.31 billion in the same period last year
• Earnings per share: estimated $0.72, versus $0.62 in the same period last year

3M had a tough first-quarter report in April. Shares of the stock fell 8% after the company slashed its full-year outlook and announced a restructuring plan that would cut about 2,000 jobs worldwide. It also missed analyst estimates for revenue and earnings.

All eyes will be on whether the Dow Jones Industrial Index member has recovered from its first-quarter lows and found a way to improve its 2019 forecast. Investors will look at its industrial and electronics and energy segments in particular, as they were the worst-performing sectors for the company in the first quarter.

The company's July 25 earnings call should be able to shed light on how effective 3M's restructuring efforts have been so far. Phone in to learn if the cost-cutting has been able to stabilize the key end markets the company struggled in earlier this year.

Here are Wall Street's quarterly estimates heading into the week:

• Revenue: estimated $8.03 billion, versus $8.39 billion in the same period last year
• Earnings per share: estimated $2.05, versus $2.59 in the same period last year