The Dow Jones industrial average roared to a new all-time high Thursday, as investors continued their bullish welcome of President-elect Donald Trump.

Thanks in part to strong performance from individual companies like Goldman Sachs – whose stocks had gained about 5 percent in midday trading – and in part to positive business and financial sentiment over Trump's victory, the Dow surged to record-setting intraday levels – up more than 283 points from where it ended Wednesday.

The gains come a day after the indicator surprisingly ballooned more than 256 points, just missing an end-of-day record, and the Dow is now on pace to break its record close on Thursday. The Standard & Poor's 500 index, meanwhile, was up a more modest 0.6 percent in afternoon trading, while the Nasdaq composite index had dropped about 0.3 percent, thanks mostly to weakness in tech stocks.

The Dow gains, in particular, have baffled analysts that had previously projected massive losses in the event of a Trump victory. It's worth noting that Dow futures at one point early Wednesday morning were down more than 800 points as those on Wall Street and around the world came to terms with a President Trump.

Stocks also had slipped for more than a week prior to the election, as polls between Trump and Democratic nominee Hillary Clinton tightened.

"Certainly, the shock and awe of a Trump victory – most people around the world did not expect that. We saw that reflected in the overnight futures," Keith Bliss, a senior vice president and director of sales and marketing at Cuttone & Company, told CNBC in an interview Wednesday.

But stocks over the last two days have bucked expectations as Trump's victory appears to be igniting the market rather than causing an implosion. Investors have applauded Trump's poise in his victory speech and appearance Thursday beside President Barack Obama. And the businessman-turned-president-elect's promises to repeal regulations and restrictions weighing on the private sector have been viewed favorably by investors and financiers.

"The president-elect's more conciliatory tone and pledge to work together with his opponents came as a positive surprise to market participants, many of whom had expected more of the aggressive rhetoric that marked his campaign," Mark Haefele, global chief investment officer at UBS Wealth Management, said in a statement Wednesday analyzing the market's response to Trump.