Dow closes down 800 points as bond sell-off rattles markets

Stocks closed down significantly on Wednesday as bond yields spiked amid deficit concerns centered on a tax cut measure under consideration in the U.S. House as part of a megabill supporting President Donald Trump's second-term agenda.

The Dow Jones Industrial Average closed down 817 points, or 1.9%, while the S&P 500 declined 1.6%. The tech-heavy Nasdaq dropped 1.4%.

The sell-off on Wall Street coincided with a surge in bond yields, which in turn raised the cost of U.S. borrowing and stoked investor fears about the wider impact across the economy.

The 10-year Treasury yield jumped from 4.48% to 4.58%, reaching its highest level since February.

The nonpartisan Congressional Budget Office on Tuesday found the tax policies backed by Trump would add $3.8 trillion to the national debt.

In addition to extending the 2017 Trump tax cuts, the "One Big Beautiful Bill Act" contains changes to Medicaid and immigration policy, among other measures. Republican members of the House are aiming to pass the bill by Memorial Day.

This is a developing story. Please check back for updates.