Here are the most important news, trends and analysis that investors need to start their trading day:

• Stock futures flat as investors deal with a flood of earnings
• Microsoft, Alphabet report better-than-expected results
• Robinhood shares sink as crypto trading slows
• FDA panel recommends Covid shots for younger kids
• Democrats unveil billionaires' tax to help pay for Biden agenda

1. Stock futures flat as investors deal with a flood of earnings

U.S. stock futures pointed to a rather flat open Wednesday even as Dow stocks Coca-Cola and McDonald's shares soared nearly 3% in the premarket each on better-than-expected quarterly earnings and revenues. Coca-Cola hiked its annual outlook again.

• Dow stock Boeing was also higher despite weaker quarterly results and a $183 million charge due to issues around 787 Dreamliner flaws.
• General Motors fell roughly 1.5% in the premarket even after strong quarterly results and guidance toward the high end of its previous guidance for the year.
• Ford reports after the bell.

The Dow Jones Industrial Average and S&P 500 on Tuesday rose modestly to record closes. The Nasdaq also inched higher, now less than 1% away from its latest record close on Sept. 7.

2. Microsoft, Alphabet report better-than-expected results

Dow stock Microsoft rose 2% in Wednesday's premarket, the morning after handily beating estimates on fiscal first-quarter earnings and revenue. Microsoft benefited from significant growth in its cloud computing business.

Alphabet shares were under modest pressure in premarket trading. The Google parent reported late Tuesday third-quarter earnings and revenue that exceeded estimates. However, YouTube ad revenue and Google's cloud revenue were below estimates.

3. Robinhood shares sink as crypto trading slows

Shares of Robinhood tumbled nearly 10% in Wednesday's premarket, below their IPO price, the morning after delivering a huge revenue miss for the third quarter as cryptocurrency trading dropped off. Robinhood issued a much wider adjusted quarterly loss than expected. The company also said that, barring any change in the market environment, the headwinds that dragged down last quarter — such as lower retail trading activity — will persist into year-end.

4. FDA panel recommends Covid shots for younger kids

A key Food and Drug Administration advisory committee has recommended a lower dose of Pfizer's Covid vaccine for kids ages 5 to 11, a critical step in getting some 28 million more children in the U.S. protected against the virus as the delta variant spreads. Signoff from the full FDA and the Centers for Disease Control and Prevention, which could happened in days, is needed for shots to begin.

Merck has signed a licensing agreement with a U.N.-backed public health organization that will enable affordable global access for molnupiravir, the U.S. drugmaker's promising oral antiviral pill to treat Covid. Molnupiravir was invented at Emory University and licensed to Ridgeback Biotherapeutics, which partnered with Merck.

5. Democrats unveil billionaires' tax to help pay for Biden agenda

Senate Democrats on Wednesday unveiled a new billionaires' tax proposal, an entirely new entry in the tax code designed to help pay for President Joe Biden's sweeping domestic policy package and edge his party closer to an overall agreement. The billionaires' proposal, coupled with a new 15% corporate minimum tax, would provide alternative revenue sources that Biden needs to win over party holdouts.

— The Associated Press contributed to this report. Follow all the market action like a pro on CNBC Pro. Get the latest on the pandemic with CNBC's coronavirus coverage.