10 things you need to know before the opening bell (SPY, SPX, QQQ, DIA, SNAP, COST)

2 of the US's biggest allies could be spared from Trump's tariffs. The White House press secretary, Sarah Huckabee Sanders, said proposed tariffs on steel and aluminum could have carve-outs for Canada and Mexico that are "based on national security" and could eventually extend to other countries.

Goldman Sachs' top economist says Trump's tariffs could be the most damaging for America since Nixon's. Jan Hatzius, the chief economist at Goldman Sachs, says the possibility of a full-scale protectionist stance from the White House is what makes President Donald Trump's tariffs different from every other president's going back to Richard Nixon.

China fires a warning shot. "As for our trade frictions, history teaches that trade war is never the right solution," China's foreign minister, Wang Yi, said at the National People's Congress. "In a globalized world it is particularly unhelpful as it will harm the initiator as well as the target country."

China just recorded another large trade surplus with the US. China recorded a $20.96 billion trade surplus with the US during February, according to data from the General Administration of Customs. In total, China's trade surplus came in at $33.74 billion.

Bitcoin traders are angry that Mt. Gox's crypto stash is being 'dumped' on the market. Bankruptcy trustees for Mt. Gox, the crypto exchange that went bust in 2014, have sold more than $400 million worth of bitcoin so far, and traders are worried the selling is affecting its price.

Snap is planning its 'largest layoffs to date.' The layoffs are strictly in the engineering department and could affect more than 100 engineers, Cheddar's Alex Heath says.

Costco sees a big jump in online sales. The warehouse-club giant beat on both the top and bottom lines in the second quarter as online sales soared 28.5%.

Stock markets around the world trade mixed. Hong Kong's Hang Seng (+1.52%) paced the gains in Asia, and Germany's DAX (-0.38%) trails in Europe. The S&P 500 is set to open little changed near 2,725.

Earnings keep coming. American Eagle, Dell Technologies, and Kroger report ahead of the opening bell.

US economic data trickles out. Initial claims will be released at 8:30 a.m. ET. The US 10-year yield is unchanged at 2.88%.