Stock market today: Dow, S&P 500, Nasdaq gain steam as bonds rally, Trump pauses tariffs on Canadian goods

US stocks gained steam on Wednesday after the US Treasury Department said it would increase buybacks of long-dated government debt, leading to yields sharply pulling back, and President Trump paused tariffs on Canadian goods that were scheduled to take effect at midnight.

The Dow Jones Industrial Average ( ^DJI ) and the S&P 500 ( ^GSPC ) gained 0.4%, while the tech-heavy Nasdaq Composite ( ^IXIC ) also rose by 0.4%.

In individual stocks, Moderna ( MRNA ) shares doubled after the company reported positive results from its late-stage trial of a melanoma vaccine developed with Merck ( MRK ).

Stocks turned higher after Treasury yields eased from their highest levels in years. Bond prices, which move inversely to yields, rallied after the US Treasury Department said it would increase buybacks of long-dated government debt "by at least double" for securities from the 10-year to 30-year sector.

The 10-year yield ( ^TNX ) fell by 5 basis points to 4.65%, while the 30-year yield ( ^TYX ) declined by 8 basis points to 5.20% after hitting its highest level since 2007 earlier this week.

Investors also watched the trade front after Trump posted on Truth Social late Tuesday night that he paused the 50% Canadian tariffs for three days "based on the fact that Canada and the U.S.A., subject to the finalization of documents, have a DEAL!"

The announcement came after 11th-hour talks between Trump officials and Canadian Prime Minister Mark Carney's team. While experts have said the tariffs would have had limited economic ramifications, they represent a strong signal of upcoming negotiations for the US-Mexico-Canada Trade Agreement (USMCA).

Investors will get the Fed's meeting minutes from the FOMC's July meeting later on Tuesday, which promise clues into policymakers' debates on inflation, policy, and other key economic data.