Heavy selling marks end to wild week for stocks

The Dow dropped 296 points, or 1.2%, on Friday, capping off another wild week of steep losses and fleeting rebounds.

The Nasdaq tumbled 2.1% as slowing revenue growth from Amazon and Alphabet unnerved investors. Amazon plunged 8%.

The good news is that markets recovered from even steeper losses. The Dow had been down as many as 539 points and the Nasdaq had plunged 3.6%.

The S&P 500 briefly slipped into a correction before bouncing off the lows.

Still, it was another dreadful week on Wall Street, especially in the tech world. The Nasdaq plunged 3.8% on the week, its worst since March. The index is on track for its worst month since November 2008.

"The sentiment in tech is remarkably poor," said Nicholas Colas, co-founder of DataTrek Research. "Technology was priced for perfection. But we live in an imperfect and increasingly unpredictable world."

Friday's turbulence is just the latest in a series of erratic moves on Wall Street. The Dow soared 401 points on Thursday, after plunging more than 600 points the day before.

A variety of fears have sent stocks into a tailspin this month. All of the Dow and S&P 500's gains for the year have been wiped out. And the Nasdaq is on track for its worst month since November 2008.

Although Amazon reported record profit, the e-commerce juggernaut's revenue only increased by 29%. That marks a slowdown from 39% in the second quarter. The weaker-than-expected revenue and outlook underscores concerns that investors got too euphoric about highflying stocks.

Google owner Alphabet (GOOGL) declined 2% after saying that its revenue growth slowed more than analysts anticipated.

"They've been the momentum stocks. If they go down, they drag the market with them," said JJ Kinahan, chief market strategist at TD Ameritrade.

And Snap (SNAP) plummeted as much as 17% after failing to curb an exodus of users. Snap closed down 10%.

"Just plain brutal," Paul Hickey, co-founder of Bespoke Investment Group, wrote to clients.

Not all tech results were disappointing though. Intel (INTC) recorded stellar chip sales and upgraded its outlook on Thursday. Shares of the chip giant rose 3%.

Even though major companies are minting money, their top-line results have been less impressive. About 57% of S&P 500 companies have reported revenue that beat expectations, according to Refinitiv. That's well below the one-year average of 73%.

Will economic strength last?

Markets are starting to price in slower economic and profit growth as the bull market and business cycle age. The stimulus from tax cuts will eventually fade and the Federal Reserve's interest rate hikes may also weigh on the economy.

In fact, the S&P 500 is now trading below where it was on December 22, 2017, the day President Donald Trump signed the tax cuts into law.

Investors are also worried about how the economy is holding up under pressure from slowing global growth and trade wars.

New numbers released on Friday show the US economy grew at a healthy 3.5% pace in the third quarter. The GDP growth, largely in line with expectations, represents a modest deceleration from the brisk 4.2% growth in the fourth quarter.

Colas said he's confident the bull market isn't over. Investors are merely anticipating a deceleration in profit and economic growth.

"I strongly believe this is a correction. Underlying economic fundamentals are still very good," said Colas.

Global markets have also been in turmoil. European markets traded sharply lower, while Asian markets closed in the red.