Here are five things you must know for Wednesday, April 18:  

1. -- Stock Futures Rise Modestly

U.S. stock futures were up modestly on Wednesday, April 18, as investors weighed the impact of a strong start to U.S. corporate earnings season but continued to remain concerned over the fate of global economic growth and protectionist trade policies from the White House.

Contracts tied to the Dow Jones Industrial Average rose 66 points, while those linked to the broader S&P 500 gained 8 points. Futures for the Nasdaq rose 19 points.

Donald Trump tweeted Tuesday, April 17, that he doesn't intend to bring the U.S. back into the Trans-Pacific Partnership trade deal, a comment that suggested his two-day summit with Japan's Prime Minister Shinzo Abe wasn't bringing the two sides closer to an agreement on narrowing the latter's $623 billion U.S. trade surplus.

Stocks rose on Tuesday, as investors reacted to strong earnings from Goldman Sachs Group Inc. (GS) - Get Report and Netflix Inc. (NFLX) - Get Report . The Dow rose 213 points, or 0.87%, to 24,786, and turned positive for the year. The S&P 500 gained 1.07% and the Nasdaq rose a sharp 1.74%.

Morgan Stanley's  (MS) - Get Report  profit in the first quarter rose 38%. Earnings were $1.45 a share in the quarter, topping estimates of $1.25. The stock rose 1.8% in premarket trading. 

Earnings reports are also expected Wednesday from Abbott Laboratories (ABT) - Get Report and American Express Co. (AXP) - Get Report .

Goldman Sachs and Abbott are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells the stocks? Learn more now.

The U.S. economic calendar on Wednesday includes Oil Inventories for the week ended April 13, at 10:30 a.m. ET, and the Federal Reserve's "Beige Book" at 2 p.m.

If you'd like to receive the free "5 Things You Must Know" newsletter, please register here.

2. -- IBM's Profit Margins Slump

International Business Machines Corp. (IBM) - Get Report shares were tumbling 5.3% in premarket trading on Wednesday after the tech giant reported a weaker-than-expected profit margin in an otherwise solid set of first-quarter earnings.

IBM said revenue for the three months ended in March rose 5% to just more than  $19 billion, its second consecutive quarter of sales growth after two years of declines. The company noted, however, that its gross margin, a key measure of profitability, slid 0.8% from the same period last year to 43.7%, a figure that fell far short of analysts' forecasts.

Compared with some of the prior IBM earnings reports that have sparked selloffs, the numbers provided in Big Blue's latest release weren't especially harsh, wrote TheStreet's Eric Jhonsa. But the fact that IBM shares were falling in response to the numbers might say something about how, following years of underperforming IT peers and promising major top- and bottom-line turnarounds, investor patience has run thin.

Image placeholder title

3. -- Blown Southwest Jet Engine Had 'Metal Fatigue'

A preliminary examination of the blown jet engine of the Southwest Airlines (LUV) - Get Report plane that left a businesswoman hanging half outside a shattered window showed evidence of "metal fatigue," according to the National Transportation Safety Board, the Associated Press reported.

Passengers scrambled to save the woman from getting sucked out the window that had been smashed by debris. She later died, and seven others were injured.

The pilots of the twin-engine Boeing 737 bound from New York to Dallas with 149 people aboard took it into a rapid descent Tuesday and made an emergency landing in Philadelphia.

The National Transportation Safety Board sent a team of investigators to Philadelphia.

In a news conference late Tuesday, NTSB Chairman Robert Sumwalt said one of the engine's fan blades was separated and missing. The blade was separated at the point where it would come into the hub and there was evidence of metal fatigue, Sumwalt said.

4. -- UAL, CSX Shares Higher on Profit Beats

United Continental Holdings Inc.

(UAL) - Get Report

, the parent of United Airlines, rose 3.2% in premarket trading on Wednesday after reporting first-quarter earnings and sales that beat analysts' expectations.

Adjusted earnings in the quarter were 50 cents a share, topping forecasts of 44 cents. Revenue rose to $9.03 billion vs. estimates of $9.02 billion.

Meanwhile, CSX Corp. (CSX) - Get Report gained more than 5% in after-hours trading on Tuesday after the Jacksonville, Fla.-based railroad company reported a top- and bottom-line beat for the first quarter, driven by lower costs and restructuring expenses.

5. -- Taxpayers Get an Extra Day to File

The Internal Revenue Service granted an extra day to taxpayers after its website suffered major outages that prevented online payments for much of Tuesday. 

The IRS said in a statement it was providing an extra day for taxpayers to file because of the system issues. 

Taxpayers now have until midnight on Wednesday to file their tax returns.

Because April 15 fell on a Sunday and April 16 is celebrated as Emancipation Day in Washington, this year's original tax deadline was April 17.

Retirement is coming. It's never too early -- or too late -- to plan, save and invest for the retirement you want and deserve. Let TheStreet's new premium subscription newsletter, Retirement Daily, give you the insider's edge on how to maximize and protect your most important investment, your retirement savings. Learn more about Retirement Daily and get a free trial subscription.