Major market indexes rose sharply on pent-up optimism after Congress passed the deal on taxes Tuesday and sent it to President Barack Obama to be signed into law.
Technically, the deal was a day late and it postpones a debate about spending cuts. But the fear of the default budget, which the new tax code eliminates, has been quelled.
The tax bill leaves federal tax rates intact for income up to $400,000 for individuals and $450,000 for families, circumventing concern that a large segment of the country will have less money to spend in 2013.
By close of trading, the Dow Jones industrial average added 2.35 percent or 308.41 points to 13,412.55.
In two trading sessions, the final day of trading in 2012 and this first session of the year, the Dow has added 474 points. Monday's gain was largely fueled by expectation that a budget deal was close.
The Nasdaq gained 3.07 percent Wednesday or 92.75 points to 3,112.26.
The Standard and Poor's 500 added 2.54 percent, 36.23 points, to 1,462.42.
The 10-year treasury note was off 23/32 to yield 1.84 percent.
On the New York Stock Exchange, 2,827 stocks advanced and 291 declined on a volume of 4.1 billion shares traded.
The euro fell to $1.3187 from Monday's $1.32. The dollar rose to 87.33 yen from 86.71 yen.
In London, the FTSE 100 index gained 2.2 percent, 129.56 points, to 56,027.37.
Markets in Japan were closed.