More pain appears to be in store for markets after their worst week to start a quarter since 2008. U.S. stock futures tumbled Sunday night when trading reopened, and markets in Asia plunged.

In the U.S., contracts tied to the tech-heavy Nasdaq-100 led the declines, down more than 3.5%. In Japan, the Nikkei 225 dropped 6% shortly after the open. Japan’s exchange operator briefly called a halt to trading in Nikkei stock futures on Monday. Bitcoin and oil prices fell sharply, too.

To recap: Tariffs on just about everything the U.S. imports took effect Saturday and are due to be raised on some countries on Wednesday.

Trump, who was golfing in Florida over the weekend, urged Americans to stay the course through what he called an economic revolution, promising in a social-media post that “it won’t be easy, but the end result will be historic.”

Here’s what else you need to know:

Futures tied to the major U.S. indexes dropped more than 2%, paring earlier declines.

Israeli Prime Minister Benjamin Netanyahu is set to be the first world leader to hold in-person talks with Trump about the tariffs. U.S. officials said more than 50 countries had reached out to start negotiations, but Trump reiterated that tariffs are “the only way” to cure trade deficits.

Billionaire investor Bill Ackman called for a 90-day pause on the implementation of the tariffs, saying they are a mistake.

First-quarter earnings will start rolling in this week, with reports due from Levi Strauss, Delta Air Lines and CarMax. Friday is likely to be the most eventful day, with JPMorgan Chase, Wells Fargo and BlackRock on deck.