One by one, the concerns that have hung over the US stock market have faded.

Fears that the US economy would dip into a recession this year have eased. The Federal Reserve seems to be finished raising interest rates for the foreseeable future, and optimism has increased that the US and China could end their trade war.

But if the January snap back (it was the best start to a year for stocks in decades, after the worst December for stocks in an even longer period), is to sustain itself, big technology companies likely will have to lead the way.

So far this year, they have not done that.

For much of the past decade, the fate of the stock market has been tied to the performance of a handful of the largest tech companies: Amazon, Apple, Alphabet, Facebook, Microsoft and Netflix led the market from one record to the next.

By the end of August, their sway over the direction of the S&P 500 exceeded all but two of the index’s 11 sector groupings. As the index pushed to a record high this past summer, the rise in those six companies’ shares accounted for half its gain.

They led on the way down, too, dragging the broader market lower during the final three months of 2018 and nearly ending the longest bull market on record.

So it’s notable, then, that as the S&P 500 rallied nearly 8 per cent in January, the big technology stocks accounted for just 17 per cent of the benchmark’s rise, according to data from Howard Silverblatt, senior index analyst for S&P Dow Jones Indices.

What happened?

The companies have faced a fundamental question since late 2018: Could they continue to pull in new users and generate more sales in a slowing global economy? Sales growth had begun to slow in the second-half 2018, and earnings updates in January haven’t fully resolved investors’ concerns about their trajectory.

“This is the first quarter in my memory that technology has on the whole had worse metrics than the S&P 500,” said Sameer Samana, senior global market strategist at Wells Fargo Investment Institute, referring to the earnings and revenue growth rate of big technology companies.

After Apple warned of diminishing demand for new iPhones in China this year, its forecast for the current quarter wasn’t as dire as many on Wall Street had feared. The stock has gained 7.7 per cent since then.

Still, the iPhone maker reported a 15 per cent drop in revenue, including a 27 per cent decline in China, and its results indicated a difficult road ahead. Its stock remains nearly 30 per cent below its peak.

Amazon reported record profits and revenue. But its shares were down 5.4 per cent on February 1 in part because revenue from online shopping slowed and the growth of Prime memberships appeared to have plateaued.

Microsoft shares have fallen 3.4 per cent since it reported. Revenue at the software giant has surged in recent years as its bet on cloud computing has paid off, but there were continued signs that the acceleration could be tapering off.

Facebook, whose shares were the most battered among the big tech companies this past year, was perhaps the bright spot this earnings season. Despite a string of scandals, the social network generated record revenue and profit in 2018. Its shares have jumped 10.5 per cent since January 30.

Netflix also said revenue would grow more slowly this quarter. Its stock is down almost 3.8 per cent since it reported January 17.

There is a big caveat to all the hand-wringing about slowing growth: All five companies still generate huge revenue. And should Beijing and Washington reach an agreement in the trade war, sales could pick up if the global economy, particularly China’s, begins to gain speed.

“There was real concern that tech was the canary in the coal mine of what would be a very dark 2019,” said Daniel Ives, an analyst at Wedbush Securities covering technology companies. “Thus far a lot of those fears are proving overblown. That could set the stage for tech to make new highs this year, depending on what happens with China.”