10 things you need to know before the opening bell

Here's what you need to know:

President Donald Trump asked former FBI director James Comey to shut down the investigation into former National Security Adviser Michael Flynn, The New York Times reports. "The President has never asked Mr. Comey or anyone else to end any investigation," the White House said in a statement.

Global markets are in risk-off mode. Gold and Treasurys are rallying as US stock futures decline. Major indexes across Europe and Asia are in the red.

Target beats. The retailer reported a smaller-than-expected drop in quarterly comparable sales, as sales picked up in March after a slow start to the quarter.

Britain's unemployment falls to a 42-year low of 4.6%. But wage growth is falling as Brexit squeezes consumers, according to the latest data released by the Office for National Statistics.

Snap faces IPO-related allegations. A former employee who claims Snap lied to investors ahead of its initial public offering has escalated his lawsuit against the company and is seeking protection under whistleblower laws.

The Securities and Exchange Commission reconsiders a risky ETF. According to The Wall Street Journal, the SEC is reviewing its initial approval of a risky, exchange-traded fund that promises four times the daily moves of S&P 500 futures - a so-called quadruple-levered ETF.

The New York Stock Exchange is slowing down trading for a key market. The NYSE has won approval for plans to introduce a 350-microsecond delay in trading on its market for small-cap companies. The speed bump was "designed to create a competitive trading model to IEX," America's newest stock exchange, NYSE said.

Twitter cofounder Biz Stone is rejoining the company after almost six years away. Stone returns amid a stall in new-user growth.

Earnings reporting is light. American Eagle Outfitters is set to announce ahead of the opening bell. Cisco and L Brands are scheduled after the market closes.

Oil inventories are on tap. The Energy Information Administration will release its latest weekly report on stockpiles at 10:30 a.m. ET. The American Petroleum Institute said Tuesday that stockpiles rose by 882,000 barrels, missing the expectation for a draw by 2.3 million.