Here are the most important news, trends and analysis that investors need to start their trading day:1. Stock futures under pressure ahead of U.S. retail sales dataA trader works on the trading floor at the New York Stock Exchange (NYSE) in New York, August 9, 2021.Andrew Kelly | ReutersStock futures fell Tuesday as traders awaited the release of key economic data about the U.S. consumer. Futures tied to the Dow Jones Industrial Average slid 22 points, or 0.6%. S&P 500 and Nasdaq 100 futures dropped 0.5% and 0.4%, respectively. Tuesday’s declines came a day after the Dow and S&P 500 set fresh record highs.Retail sales data for July is slated for release at 8:30 a.m. ET. Economists expect sales to have dropped by 0.3%, according to Dow Jones. Excluding autos, however, retail sales are expected to have risen by 0.2%.2. S&P 500 doubles from Covid pandemic bottomMonday was a banner day for the S&P 500 in more ways than one. The benchmark closed at 4,479.71, up 100.2% from its Covid closing low of 2,237.40 reached March 23, 2020. It marked the fastest bull market doubling off a bottom since World War II, according to data from S&P Dow Jones Indices. The blistering gains over that time came as the Federal Reserve launched a massive bond buying program and kept rates low, while the government injected trillions of dollars into the economy through relief spending.3. Retail giants Home Depot and Walmart report earningsA customer wearing a protective mask loads lumber at a Home Depot store in Pleasanton, California, Feb. 22, 2021.David Paul Morris | Bloomberg | Getty ImagesShares of Home Depot fell more than 3% in the premarket after the home improvement retailer’s same-store sales for the previous quarter missed expectations. Home Depot reported earnings per share and revenue for the quarter that beat analyst expectations but same-store sales for the fiscal second quarter rose by disappointing 4.5%. Analysts expected a gain of 5%, according to StreetAccount. The slight miss comes a year after consumers flocked into its stores to buy home improvement supplies while they were stuck inside due to the pandemic. A shopper wearing a protective mask shops in a Walmart store on May 18, 2021 in Hallandale Beach, Florida.Joe Raedle | Getty Images4. U.S. is expected to recommend Covid vaccine booster shot 8 months after second doseFourth-year medical student Anna Roesler administers the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine at Indiana University Health, Methodist Hospital in Indianapolis, Indiana, December 16, 2020.Bryan Woolston | ReutersU.S. health experts are expected to recommend Americans of all ages receive a Covid vaccine booster shot eight months after they receive their second dose, The Associated Press reported, citing sources. The report said an announcement on booster shots was expected as soon as this week. The recommendation would come as new cases across the country rise amid the spread of the delta variant. Over the weekend, five states set fresh records for Covid cases.5. Flights from Kabul resume as people scramble to leave AfghanistanFrench and Afghan nationals line up to board a French military transport plane at the Kabul airport on August 17, 2021, for evacuation from Afghanistan after the Taliban’s stunning military takeover of the country. (Photo by STR / AFP) (Photo by STR/AFP via Getty Images)STR | AFP | Getty ImagesFlights from Kabul’s international airport resumed Tuesday following a frenzied day that saw thousands of Afghans run into the tarmac in attempts to leave Afghanistan. “The situation is stabilizing but obviously we are monitoring it very carefully,” U.K. Foreign Secretary Dominic Raab told Sky News on Tuesday. “I do think that the airport is more stable today than it was yesterday, and we need to make sure that we consolidate that in the days ahead.” The chaos in the Middle Eastern nation came after the Taliban took over Kabul on Sunday as the U.S. pulled its troops from the country. “I stand squarely behind my decision. After 20 years I’ve learned the hard way that there was never a good time to withdraw U.S. forces,” President Joe Biden said Monday.— Follow all the market action like a pro on CNBC Pro. Get the latest on the pandemic with CNBC’s coronavirus coverage.