NEW YORK (TheStreet) -- Stocks pared losses by latemorning Wednesday in a volatile day of trading. The Dow Jones Industrial Average had dropped 153 points at its session low after Federal Reserve Chair Janet Yellen warned of potentially overstretched equity valuations.

Equities were also under pressure as weaker private payrolls numbers from ADP triggered fears ahead of the official U.S. jobs report on Friday and amid a global selloff of government bonds.

The S&P 500 was down 0.21%, the Dow fell 0.32%, and the Nasdaq slid 0.18%.

Crude prices hit fresh 2015 highs after oil inventories showed a surprise drop, the first in 17 weeks. Supplies were down 3.9 million barrels for the week ended May 1. Economists had forecast an increase of 1 million barrels. West Texas Intermediate crude oil rose 2.6% to $61.99 a barrel.

Yellen said market valuations were "generally quite high," though noted the Fed was not seeing signs of a bubble. Yellen's comments came in a joint appearance with International Monetary Fund managing director, Christine Lagarde, at a conference in Washington. 

ADP reported 169,000 jobs were added to private payrolls in April, lower than 189,000 jobs in March. Economists had expected 193,000 jobs to have been added last month.

"ADP's estimated April gain in private payrolls was 169K, the weakest since Jan 2014. Its predictive power for the BLS monthly employment report has been poor in recent months," cautioned RBS Securities' Guy Berger. "It's flubbed the call four of the past six months."

U.S. Treasury yields were trading close to recent highs. Yields reached their highest point since early March on Tuesday as U.S. Treasuries sold off alongside German, Spanish, Italian and U.K. bonds.

"The most important thing to me is what's causing people to sell bonds," Art Hogan, chief market strategist at Wunderlich Securities, told CNBC. "The 10-year moving higher (adds to) the picture the global economy is improving and that's going to factor itself into the market at some point."

Groupon (GRPN) fell 5.3% after reporting a first-quarter loss of $14.3 million, narrower than a year-ago loss of $37.8 million. Second-quarter guidance came in light with earnings expectations of between 1 cent to 3 cents a share missing estimates.

Apple (AAPL) shares were on watch after reports the Federal Trade Commission is investigating the company's Beats Music. According to reports, the company used its iTunes platform to undercut competitors.

Twitter (TWTR) is reportedly about to undergo another C-suite shakeup. The social network is set to appoint Chief Financial Officer Anthony Noto as head of the marketing department, replacing Senior Vice President of Product Kevin Weil, according to The Wall Street Journal. Noto is reportedly now in charge of corporate development, strategy and finance.

Herbalife (HLF) surged more than 15.2% after earning $1.29 a share in its recent quarter, rocketing past estimates of $1.01 a share. Sales were down nearly 13% to $1.11 billion, though beat forecasts of $1.09 billion.

Alexion Pharmaceuticals (ALXN) was lower after agreeing to acquire Synageva BioPharma (GEVA) in a cash-and-stock deal worth $230 a share, or $8.4 billion. Alexion expects the acquisition to achieve cost synergies this year. Synageva rocketed 115% higher.

Stocks sold off on Tuesday, with the Nasdaq and S&P 500 down more than 1%, after weak trade data prompted worries that revised macro numbers could show the U.S. economy contracted in the first quarter.

If you liked this article you might like

Dow Soars Over 250 Points to Post Its Fourth Straight Day of Gains
Inflation, Chipotle, Credit Suisse and Sam's Club - 5 Things You Must Know

Inflation, Chipotle, Credit Suisse and Sam's Club - 5 Things You Must Know

Will Inflation Set Stocks' Hearts Aflutter or Be a Poison Arrow? -- Market Recon

Will Inflation Set Stocks' Hearts Aflutter or Be a Poison Arrow? -- Market Recon

The Really Big Money Rushes to Super Bowl

The Really Big Money Rushes to Super Bowl

What Warren Buffett's Two Successors Could Still Learn From the Billionaire

What Warren Buffett's Two Successors Could Still Learn From the Billionaire