The Dow Jones Industrial Average surged more than 300 points, or 0.69%, at midday, heading for a record close. The S&P 500 lost less than 0.1%, while the Nasdaq Composite slipped 0.37%. The Russell 2000 Index is up 1.53%.

Bitcoin, which is likely to benefit from relaxed regulation after Donald Trump's election win, also soared to a record of $84,400. Stocks tied to cryptocurrencies rallied.

Five S&P 500 stocks making big midday moves are:

• Bristol-Myers Squibb  (BMY)  +11.8%

• Albemarle (ALB)  +8.5%

• Cigna (CI)  +7.8%

• Tesla  (TSLA)  +5.8%

• Epam Systems  (EPAM)  +5.2%

The worst-performing five S&P 500 stocks with the largest midday drop are:

• Monolithic Power Systems  (MPWR)  -19.5%

• AbbVie  (ABBV)  -11.7%

• Super Micro Computer  (SMCI)  -7.4%

• Moderna  (MRNA)  -7.4%

• Newmont (NEM)  -6.5%

Stocks also worth noting include:

• Nvidia  (NVDA)  -1.9%

• Apple  (AAPL)  -2.3%

• Humana  (HUM)  -2.4%

• Coinbase  (COIN)  +21.4%

• Robinhood  (HOOD)  +10.8%

Tesla gained more than 5% as investors were optimistic about the EV maker after Donald Trump’s presidential win. The stock is up more than 40% since Nov. 5, topping $1 trillion in market value.

Elon Musk had previously contributed at least $130 million to Trump’s campaign efforts. Wedbush analyst Dan Ives noted that a Trump administration could favor Tesla.

Related: Top analyst overhauls Tesla stock price target amid post-election surge

“Tesla has the scale and scope that is unmatched in the EV industry and this dynamic could give Musk and Tesla a clear competitive advantage in a non-EV-subsidy environment, coupled by likely higher China tariffs that would continue to push away cheaper Chinese EV players (BYD, Nio, etc.) from flooding the U.S. market over the coming years,” Ives said in a note, CNBC reported.

Musk recently forecast 20%-30% vehicle-sales growth next year.

Cigna confirmed Monday that it was not pursuing a merger with Humana. Cigna is up 8%, while Humana lost 2%.

The two health insurance giants, valued at a combined $125 billion, explored a merger last year, but Cigna backed out over pricing disagreements, according to Bloomberg.

Related: Humana stock higher on key merger report after Medicare Advantage hit

“With the Republican win last week, there was speculation by investors that the antitrust concerns may decline enough to make the deal possible,” Morningstar analyst Julie Utterback said, calling the announcement "unusual."