S&P 500 has best week since 2013 by Tom Huddleston, Jr. @FortuneMagazine October 24, 2014, 7:04 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons The stock market proved more or less immune to Ebola on Friday, as the three major U.S. indices rose sharply in what was one of the market’s strongest weeks this year. The Dow Jones Industrial Average gained almost 128 points, or 0.8%, on Friday to close at 16,805, finishing the week up by 2.6%. The S&P 500 improved by 0.7%, to 1,965, and was up by 4.1% for the week in what was the index’s best weekly showings since last year. Meanwhile, the Nasdaq composite also gained 0.7% Friday, or 5.3% for the week, closing at 4,484. The big gains came despite the tech-heavy index suffering from an 8% drop by Amazon AMZN after the online retail giant reported disappointing third-quarter earnings Thursday afternoon. The strong week follows on the heels of more than a month of volatility during which the markets dropped sharply. Earlier this month, a massive market-wide sell-off briefly turned the Dow Jones negative for the year as investors grew concerned about global economic growth and potential interest rate hikes by U.S. Federal Reserve. Friday’s gains come one day after the market opened higher thanks to a handful of strong earnings reports from 3M MMM , Caterpillar CAT , General Motors GM , and Under Armour UA . Investors were also encouraged by a dip in jobless claims and news from Europe about a spike in German manufacturing and a drop in Spain’s unemployment. However, Thursday’s gains – which had seen the Dow Jones spike by more than 300 points early on – tailed off a bit at the end of the day after news broke that a doctor in New York City had tested positive for Ebola. The Dow closed Thursday up by 217 points while the Nasdaq and S&P 500 added gains of 2% and 1%, respectively, but there was some concern that fears of a more widespread Ebola outbreak would put a damper on the market on Friday. Fortunately, Ebola concerns subsided enough to allow for another positive day to close out the week. SodaStream International SODA was one of Friday’s biggest winners as the carbonated beverage company’s shares jumped more than 15% on a report that it is testing PepsiCo PEP products.