A tumble of blue-chip stock shares on Friday failed to erase another week of gains for Wall Street.
US stocks managed to claw back most of the losses from the beginning of 2015 buoyed by a larger-than-expected stimulus from the European Central Bank, generally higher corporate earnings and a burst of buying in big tech firms.
The Dow Jones Industrial Average put on 0.9 percent to end the week at 17,672.60, and the broader S&P 500 rose 1.6 percent to 2,051.82.
The Nasdaq Composite outdid both with a 2.7 percent surge to 4,757.88.
The ECB's announcement of a 60 billion euro-per-month ($67 billion) quantitative easing stimulus program was the strongest incentive for buying, giving the Dow a 1.5 percent boost on Thursday and the Nasdaq 1.8 percent.
It was seen as a strong commitment to fight deflation in the eurozone and restore growth, and it sent the dollar sharply higher on the euro.
From $1.156 per one euro at the beginning of the week, the dollar climbed to $1.112 Friday before pulling back slightly.
Patrick O'Hare of Briefing.com called the buying surge Thursday a knee-jerk reaction.
"There was a lot of back-slapping of ECB President Mario Draghi after he announced a larger than expected, and open-ended, QE program. The jury is out on whether it will achieve the economic ends it is designed to achieve," said Patrick O'Hare of Briefing.com.
"We understand the ECB is trying to get things untrenched, but with a lack of pro-growth fiscal and structural reforms in the euro area, the QE program could be LOA -- limp on arrival."
Earnings were generally on the upside of expectations and outlooks given by companies mostly positive -- especially in the fuel-price sensitive industries like the airlines, where shares rose 8 percent during the week.
The prospect of continued low interest rates but a stronger dollar boosted the financial sector, which gained about 2.5 percent.
But even as the outlook for oil remained bleak, with the crude price stuck below $50, oil exploration and production companies and oilfield services companies were also generally higher.
The industry has already begun top sharply cut back, with exploration budgets being slashed and services industry leaders Baker Hughes, Halliburton and Schlumberger announcing a collective 17,000 job cuts. More are expected.
- Week ahead -
Various quarterly reports in the tech companies helped fire the sector at large. Weekly gains in e-commerce firms topped 6 percent; social media companies gained 4 percent; and search engines were also about 4 percent higher.
Google gained 6.3 percent and Twitter 5.7 percent amid rumors Google wants to buy Twitter.
The coming week will be swamped with quarterly earnings reports -- 142 companies to be exact.
"It's important to get the health of corporate America. Next week we will get a bigger picture," said Art Hogan of Wunderlich Securities.
Lee Munson of Portfolio LLC said the broader range of earnings reports could show how cheap oil is affecting companies, including which ones are able to mask other problems with the lower fuel costs.
"Bad earnings might be hidden by the lower cost of energy," he said.
The week ahead also brings a new policy meeting of the Federal Reserve. The meeting will likely spur more speculation on when it will hike interest rates.
But Fed watchers do not expect any more precision to repeated signals of a possible rate increase around mid-year.