Dow Dives More Than 500 Points As Trade Worries Multiply

• The Dow, S&P 500 and Nasdaq indexes have all slumped since President Donald Trump threatened last week to slap more tariffs on Chinese imports.
• Wall Street analysts see little hope for a short-term breakthrough on trade talks between the U.S. and China, saying the sides are "dug in."

After gaining ground on Tuesday, stocks are tumbling again on growing investor fears about an escalating trade war between the U.S. and China and the collateral damage to companies and markets around the world.

The Dow fell 536 points, or 2.3%, to 25,482, shortly after the start of trade, while the S&P 500 and Nasdaq indexes both slid more than 1%. Bond yields, which move in the opposite direction of their prices, also declined in a sign investors are seeking to protect themselves amid significant volatility on Wall Street.

Markets have swung wildly this week after Washington and Beijing raised the stakes in their trade war. China allowed its currency to weaken after President Donald Trump said the U.S. would raise more tariffs on Chinese goods. 

The Treasury Department on Monday also formally labeled China a currency manipulatorfor the first time since 1994.

"Whereas a few weeks ago it seemed like a detente was likely between the two countries, at least until after next year's U.S. election, the recent round of threats of tariffs and responses suggests to us that both sides are so dug in that neither can be seen as giving into the other," Brian Gardner, an equity analyst with Keefe Bruyette & Woods, said in a report. 

The Dow, which tracks 30 large publicly traded U.S. companies, has fallen nearly 4% since Aug. 1, when Mr. Trump surprised markets by stating over Twitter that the U.S. would put a 10% tariff on $300 billion of Chinese imports come Sept. 1 unless trade talks between the countries advanced. 

The broader S&P 500 -- which notched a record high in late July -- has sunk even more during that time, losing 5%, while the tech-heavy Nasdaq has declined 4%.

-- The Associated Press contributed to this report.