Earnings playbook: Your guide to the biggest reports this week, including JPMorgan

The earnings season kicks off in earnest this week, with some of the country's biggest banks slated to report. JPMorgan Chase, Citigroup, Wells Fargo and Bank of America are all slated to post their fourth quarter results. UnitedHealth and Delta Airlines numbers are also on deck. Overall, S & P 500 earnings are expected to have grown by 1.3% during the fourth quarter on a year over year basis, according to FactSet senior earnings analyst John Butters.

That would be the second straight quarter of earnings expansion. However, Butters noted that analysts made "larger cuts than average" to earnings per share estimates heading into this reporting period. "Given concerns in the market about a possible economic slowdown or recession, have analysts lowered EPS estimates more than normal for S & P 500 companies for the fourth quarter?" Butters wrote Friday.

"The answer is yes." Take a look at CNBC Pro's breakdown of what's expected from some of this week's key reports. Friday UnitedHealth is set to report earnings before the bell, with a conference call scheduled for 8:45 a.m. ET. Last quarter: UNH posted earnings and revenue that beat analyst expectations.

The company also hiked its full year guidance. This quarter: Analysts polled by LSEG expect UnitedHealth to report double digit earnings and revenue growth from the year earlier period. What CNBC is watching: UnitedHealth's stock posted its first annual loss in 15 years in 2023, losing 0.7%, while the S & P 500 soared more than 20%.

Can the health insurance giant recover its mojo? The fourth quarter may hold some clues. Specifically, investors will keep an eye on guidance around Medicare Advantage enrollment. Shares fell on Friday after CVS said it sees membership growing to at least 800,000 this year. That's up from a forecast for 600,000 additional members.

What history shows: Bespoke Investment Group data shows UnitedHealth beats earnings expectations 93% of the time. Shares also average a 0.9% gain on earnings day. JPMorgan Chase is set to report earnings before the market opens. A call is also scheduled for 8:30 a.m. ET. Last quarter: JPM topped earnings expectations thanks to higher rates and lower credit costs.

This quarter: JPMorgan earnings are expected to have fallen slightly year over year, but revenue is seen as growing by more than 10%, LSEG data shows. What CNBC banks reporter Hugh Son is watching: "JPMorgan Chase distanced itself from its big bank peers last year, both in share performance and winning the First Republic auction.

Investors who wonder if the party can continue will seek guidance on net interest income, expenses and loan losses for 2024." What history shows: JPMorgan Chase beats earnings estimates 82% of the time, according to Bespoke. The stock has also risen in five straight earnings days. Citigroup is set to report earnings in the premarket.

Management is slated to hold a call at noon ET. Last quarter: C posted revenue that beat estimates , boosted by strong growth in the bank's institutional client and personal banking businesses. This quarter: The bank's earnings are forecast to have dropped by more than 15% on a year over year basis, according to LSEG.

What CNBC banks reporter Hugh Son is watching: "The greatest scrutiny this quarter falls on Citigroup, which is in the middle of CEO Jane Fraser's corporate overhaul. Management has said it will disclose severance costs and job cuts along with fourth quarter earnings." What history shows: Citigroup's stock typically struggles on earnings days, losing an average of 0.25%.

Shares also fell in the last two earnings days. However, the bank beats earnings expectations 76% of the time, according to Bespoke. Delta Air Lines is set to report earnings before the bell, followed by a call at 10 a.m. ET. Last quarter: DAL reported a nearly 60% year over year profit jump , citing a strong summer travel season.

This quarter: The airline is expected to report a sharp year over year earnings decline but also a 10% revenue increase, per LSEG. What CNBC CNBC airlines reporter Leslie Josephs is watching: "Delta will be first out of the gate with U.S. airline earnings this quarter and we'll be looking for clues whether 2023's robust demand could continue to grow this year, or whether consumers are spent out after the last holiday season.

Delta last month reiterated its earnings and revenue forecasts for the fourth quarter and the industry is coming off of a strong and smooth holiday season, so there might not be many surprises there. But executives will face questions about where costs — and fares cover them — are headed this year.

Look for clues on Delta's growth and hiring plans for the spring and summer, when carriers make the bulk of their money and high revenue international travel picks up." What history shows: Bespoke data shows Delta beats earnings estimates 68% of the time. However, shares have fallen on the last four earnings days.

Bank of America is set to report earnings in the premarket, with a call slated for 11 a.m. ET. Last quarter: BAC earnings beat expectations thanks to strong interest income . This quarter: LSEG data shows analysts see a 21% year over year drop in earnings. What CNBC banks reporter Hugh Son is watching: "For Bank of America, the biggest questions remain its exposure to underwater bonds purchased when interest rates were low.

A related question is what to expect from net interest income and expenses this year." What history shows: Bank of America beats earnings estimates 79% of the time, per Bespoke. The stock rose after the last nine reports were released..