NEW YORK – In a flat year overall for stocks, there was still plenty of excitement to be enjoyed – or endured – by 2015’s biggest winners and losers.

It was a year to make old guard companies shudder.

New media companies like Netflix, which rose 142 percent to notch the biggest gain in the S&P 500, became more valuable than established media companies like CBS. Amazon eviscerated traditional retailers like Macy’s and Walmart. And energy and materials companies were flattened by weak demand at a time of abundant supplies. The biggest loser was Chesapeake Energy, down almost 80 percent in 2015.

The Dow Jones industrial average, dominated by long-established companies in traditional industries, is down 1.2 percent for the year through Wednesday. The Nasdaq composite, with its heavy concentration of technology companies, is up a respectable 6.5 percent.

Netflix has enjoyed top billing before: it was the biggest gainer in the S&P 500 in 2010 and 2013, and it more than tripled in value both years.

But another big year in 2015 pushed the company’s value past established media rivals like CBS and made it about the same as Time Warner. The streaming entertainment service had 69 million subscribers at the end of the third quarter, and almost a quarter of those signed up in the last year. Netflix also continued to win fans for shows like “Orange is the New Black” and “Narcos.” The company says its service will be available in 200 countries by the end of the year.

E-commerce giant Amazon celebrated its 20th anniversary with results that sent investors into a buying frenzy. Amazon was the second biggest gainer in the S&P 500 for the year, up 114 percent through Wednesday. The company is on track to report more than $100 billion in revenue in 2015 and it has started to turn in higher profits more frequently despite a loss in the first quarter.

Its stock surge pushed the company’s market value past that of longtime competitor Wal-Mart. Wal-Mart stock fell 29 percent in 2015, which made this Wal-Mart’s worst year since 1974, when it had fewer than 100 stores. Wal-Mart was the Dow’s biggest loser.

“This year seemed to mark an inflection point for Amazon,” wrote Christine Short, an analyst at Estimize, who said Amazon was “almost solely responsible for the downfall of big box giant Wal-Mart.”

Macy’s and Staples also were among the 20 biggest losers as fewer shoppers trekked to stores and bought more goods online instead.