Stocks added to gains on Thursday, coming back from their worst losses in eight months a day earlier, as a positive quarter for Walmart (WMT) boosted consumer names, while health care lifted the Nasdaq.

The S&P 500 was up 0.67%, the Dow Jones Industrial Average increased 0.56%, and the Nasdaq added 0.9%. 

Walmart did the heavy-lifting on the Dow and S&P 500 after topping net income estimates, though revenue came in slightly weaker than expected. Earnings rose to $1 a share from 98 cents in the same quarter a year earlier. Analysts anticipated earnings of 96 cents. Sales of $117.5 billion came in below estimates of $117.8 billion. U.S. same-store sales increased 1.4%. E-commerce business climbed at its best pace in five years.

Retail consumer stocks moved higher alongside Walmart. Amazon (AMZN) , Priceline (PCLN) , Costco (COST) , Target (TGT)  and CVS Health (CVS) were each higher, while the S&P Retail SPDR ETF (XRT) added 0.5%. 

Health care shares pushed the Nasdaq into positive territory. Incyte (INCY) surged 7% after its an immune-system booster drug, combined with Merck's (MRK) immunotherapy Keytruda showed positive results in an ongoing study with advanced lung cancer patients. Around 35% of patients given the combination treatment had tumors shrink by at least 30%.

Fellow Nasdaq component AthenaHealth (ATHN) rallied 22% after activist investor Paul Singer disclosed a 9.2% stake. In an filing with the Securities and Exchange Commission, Elliott Associates' Singer said shares "are significantly undervalued and represent an attractive investment opportunity."

The Trump administration is working toward at least 3% GDP growth, a target wholly achievable, Mnuchin said in his first congressional testimony since assuming his role as Treasury secretary. Mnuchin said growth would be "achievable if we make historic reforms to both taxes and regulation." Stocks had rallied since the election on high hopes for an overhaul of the tax code, though recent political developments raised skepticism over how fast that could be achieved. 

"Markets had risen on the expectation of tax and health reform along with an infrastructure spending plan, but the constant string of high profile distractions involving the president or members of his administration has put all that into jeopardy," said Tom Siomades, head of the Investment Consulting Group of Hartford Funds. "For the markets, it is quickly becoming a credibility issue. Can this administration deliver something meaningful, and when?"

It is still too early to be trusting of this bounce, said James "Rev Shark" Deporre over on our premium site for investors, Real Money. Get his insights with a free trial subscription to Real Money. 

More details have come to light in the investigation over the Trump campaign's ties to Russia. A report from Reuters said former National Security Adviser Michael Flynn and others in Donald Trump's presidential campaign had extensive contacts with Russian officials. According to Reuters sources, Flynn and others on Trump's team made contact with contacts associated with the Kremlin at least 18 times over the final seven months of the election.  

The revelation follows news Wednesday that the U.S. Department of Justice named former FBI Director Robert S. Mueller to head a probe into allegations that Russia interfered in last year's presidential elections and any ties between the Trump campaign and Moscow.

On Twitter Thursday, Trump said the investigation was the "single greatest witch hunt of a politician in American history," and complained that the Clinton campaign and Obama administration had not been investigated despite "all the illegal acts that took place."

The latest report follows on from a turbulent week for Trump and his team. On late Tuesday, a New York Times report found that Trump asked former FBI Director James Comey to shut down the federal investigation into since-ousted National Security Adviser Michael Flynn. Flynn was forced to resign on Feb. 13 amid questions over his contact with the Russian ambassador and discussions of U.S. sanctions.

Comey wrote a memo detailing his conversation with the president shortly after it took place, according to the Times, which cited two people who read the document. It's part of a paper trail Comey created documenting what he believed to be improper efforts to influence the investigation. The president fired Comey, who was heading an investigation into the Trump campaign's alleged ties with Russia, early last week.

On Monday, news broke that Trump had divulged highly classified intelligence to Russia during a meeting last week, according to a report from The Washington Post. Trump reportedly shared top-secret information on the fight against ISIS with Russian Foreign Minister Sergey Lavrov and Russian Ambassador Sergey Kislyak in a meeting in which U.S. media was barred. The meeting had also raised eyebrows because it occurred just a day after Trump fired Comey.

These messy political developments in Washington spilled into financial markets on Wednesday in the most punishing day for stocks of 2017. The Dow fell 372 points, while the S&P 500 suffered its worst day since Sept. 9

Jobless claims in the U.S. fell in the past week, another sign of a healthy labor market. The number of new claims for unemployment benefit fell by 4,000 to 232,000. The less volatile, four-week average declined by 2,750 to 240,750. Continuing claims fell by 22,000 to 1.9 million, settling in at the lowest level since late 1988. 

Business conditions in the Philadelphia region improved at a faster pace in May, according to the latest Philadelphia Fed index. The measure increased to 38.8 in May from 22 in April, better than an expected reading of 19.6. 

Cisco (CSCO) tumbled nearly 8% after disappointing revenue guidance its current quarter. The tech company anticipates current-quarter sales to decline by 4% to 6%, indicating sales no higher than $12.13 billion. Analysts anticipated sales of $12.5 billion. Cisco also announced plans to lay off 1,100 jobs. The company had announced plans to reduce its workforce by 5,500 jobs back in August. 

Cisco is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells CSCO? Learn more now.

Ralph Lauren (RL)  slipped despite reporting a better-than-expected quarter. The fashion brand swung to a net loss of $2.48 a share from profit of 49 cents a share in the year-ago quarter. Adjusted earnings of 89 cents a share came in higher than consensus of 78 cents. Revenue of $1.57 billion came in ahead of estimates of $1.56 billion. 

Alibaba (BABA)  shares were under pressure as investors focused more on the Chinese internet giant's lower-than-expected earnings for the 2016 fourth quarter, rather than its significant top-line growth. Earnings of 63 cents a share missed estimates by 3 cents. Revenue surged 60% to $5.6 billion, $400 million above consensus.

Other earnings reports of note include L Brands (LB) , Children's Place (PLCE) , Buckle (BKS)  and Bon-Ton Stores (BONT)  . 

More than 93% of S&P 500 companies have reported earnings so far this season. Of those, just over 75% have exceeded earnings expectations, above the historical average of 64%, according to Thomson Reuters. On the topline, 63% have topped revenue estimates, a narrower beat than the average rate of 59%.

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