Whether it was oil, the health of the U.S. economy, or a series of weaker earnings results across a number of sectors, investors had more than enough to push them into panic mode. 

Stocks bottomed out near lows by market close on Friday. The S&P 500 was down 1.9%, the Dow Jones Industrial Average slid 1.3%, and the Nasdaq fell 3.3%.

This rough environment is not anything new for investors who have dealt with extreme volatility and sellofs since the beginning of the year. And it may not end any times oon.

"There's [no] good reason to expect much growth in the S&P 500 this year," Jeremy Lawson, chief economist at Standard Life Investments, told TheStreet. "There aren't a lot of catalysts to make us feel very optimistic in the current circumstances. We don't have a growth catalyst, you don't have a confidence catalyst, geopolitical developments are troubling."

Even if the Federal Reserve doesn't raise interest rates as quickly as it had indicated, he said, members "don't look like they're ready to dive back in and offer a lot of monetary policy support."

A weaker jobs report alarmed investors already concerned over the health of the U.S. economy. The U.S. saw the lowest labor growth in January since September and fell short of economists' estimates.

On the upside, the unemployment rate dropped to 4.9%, its lowest level since 2008, while average hourly earnings increased 0.5%, the highest since January 2015.

"This report was a 'mixed bag' and doesn't really give investors any clear direction," said Chris Gaffney, president of EverBank World Markets. "Market sentiment continues to have a bearish bias as investors question the strength of the U.S. recovery. This report really doesn't do anything to change that."

The silver lining was that the weaker-than-expected report added to the likelihood the Fed will delay future rate hikes until the U.S. economy shows stronger signs of improvement. The central bank raised rates for the first time in nine years in December, citing a a robust labor market as one of the reasons.

"External factors continue to represent a meaningful risk to our call for three rate hikes and the Fed has legitimate reasons to skip a hike in March if it chooses to do so," Societe Generale analysts wrote in a note. "However, the U.S. economy would have to experience a much bigger financial shock than it has to date in order to derail the momentum in the labor market and to justify keeping rates on hold for the remainder of the year."

A post-earnings selloff in LinkedIn (LNKD - Get Report ) and Tableau Software (DATA - Get Report)  triggered broader losses in the tech sector.

LinkedIn plummeted 44% after offering a first-quarter outlook that fell far short of estimates. The professional networking site expects current-quarter earnings no higher than 55 cents a share, 20 cents below forecasts. For the full year, the company expects profit between $3.05 and $3.20 a share, less than consensus of $3.70 a share.

Tableau Software tumbled 49% after management warned it was unlikely to realize benefits of certain tax assets. The news sent shares spiralling, despite the software company's better-than-expected quarter. The company earned 33 cents a share, more than double estimates.

Tableau "is now a tainted growth stock of unbelievable proportions, with the core licensing business slowing from 57% growth to 31%," said TheStreet's Jim Cramer, co-manager of the Action Alerts PLUS portfolio.

The tech sector was the worst performer on markets Friday. Industry giants including Amazon (AMZN - Get Report) , Alphabet (GOOGL - Get Report) , Apple (AAPL - Get Report) and Microsoft (MSFT) were all lower, while the Technology Select SPDR ETF (XLK) slid 2.8%.

Alphabet and Apple are holdings in Jim Cramer's Action Alerts PLUS charitable trust portfolio.
 

Energy stocks were sharply lower as crude oil pulled back from the week's highs after President Barack Obama proposed a new tax aimed at reducing carbon emissions and funding new transportation. Obama unveiled plans to levy a $10-a-barrel tax, phased in over five years.

Oil companies are already struggling with crude prices at multi-year lows. West Texas Intermediate crude fell 7.9% for the week. Oil companies such as Exxon (XOM) , Schlumberger (SLB) and ConocoPhillips (COP) tumbled.