London (CNN Business) 1. Trump on stocks: President Donald Trump suggested Tuesday that investors capitalize on crashing US stock prices by opening their wallets.

"We have companies, the greatest in the world, and they're doing really well. They have record kinds of numbers. So I think it's a tremendous opportunity to buy. Really a great opportunity to buy," Trump told reporters at the White House.

In the same briefing, however, Trump again criticized the US Federal Reserve, accusing the central bank of raising interest rates too quickly. The risk that Trump could move to fire Jerome Powell, chairman of the central bank, is one major reason why investors dumped US stocks before Christmas.

Trump also told reporters that he remains confident in Treasury Secretary Steven Mnuchin, who spoke to major bank executives over the weekend and then issued a public statement saying that lenders had "ample liquidity." The unusual statement added to investors' unease on Christmas Eve.

2. What's next for markets: The big question is how US stocks react when trading resumes on Wednesday.