Stocks struggled to determine direction on Wednesday as Wall Street took a slight pause after two days of record-making runs.

The S&P 500 and the Dow Jones Industrial Average were flat, and the Nasdaq rose 0.12%.

Wall Street extended a rally into day three on Tuesday, pushing the S&P 500 and Dow to clinch new record closing highs. The S&P 500 secured a record close of 2,152.14, its second day of record closes. The Dow climbed to 18,347.67, breaking a previous all-time record from May last year.

It's been three weeks since the United Kingdom voted to exit the European Union and Wall Street has erased all Brexit-related losses. British Prime Minister David Cameron will step down from his role on Wednesday, leaving the post to incoming PM Theresa May.

Crude oil pulled back from its highest levels in roughly a week on Wednesday after a weekly read on crude inventories showed a smaller-than-expected decline. The Energy Information Administration reported a 2.5-million-barrel decline in stocks, weaker than an expected drop of 3.25 million barrels. 

The International Energy Agency warned in its monthly report that ballooning inventories could threaten the "recent stability of prices." Output in the Middle East has risen, while production in the U.S. has shrunk, creating a short-term balance in supply.

West Texas Intermediate crude oil fell 2.3% to $45.72 a barrel on Wednesday.

Import prices climbed just 0.2% in June, below an expected 0.5% increase and well below May's 1.4% growth. Import prices excluding fuel dropped 0.3%, according to the Bureau of Labor Statistics. Export prices rose 0.8%, in line with estimates.

The "Beige Book," out Wednesday afternoon, will present an anecdotal read on how the 12 Federal Reserve districts are faring. The upcoming release covers information collected over the six weeks from mid-May to the end of June. The last Beige Book, released at the beginning of June, characterized economic growth in the 12 districts as modest.

The outcome of the Brexit vote has increased uncertainty over the U.S. economic outlook, Cleveland Fed President Loretta Mester said on Tuesday. Mester also noted the Fed has the ability to pause before determining the next interest-rate move.

"I do not think U.S. monetary policy is behind the curve yet" so it was right for the Fed to hold rates steady in June, Mester said in a speech on the economic outlook at the Australian Business Economists Luncheon in Sydney. "I expect we will be living with uncertainty for a while as the U.K. and Europe establish the terms of their new relationship."

The chances of a rate hike this year have been greatly diminished by recent rough patches in economic data and the uncertainty surrounding the United Kingdom's exit from the European Union. However, a stronger-than-expected U.S. jobs report in June reintroduced the possibility of a rate hike later in 2016.

Juno Therapeutics (JUNO) roared higher on Wednesday after the Food and Drug Administration removed a clinical hold on its Phase 2 trial of a drug for leukemia. The biotech company had slumped last week after the FDA put a hold on the trial after the death of two patients undergoing the treatment.

Amazon's(AMZN) - Get Report second annual Prime Day didn't go as smoothly as hoped for with technical glitches restricting sales early in the day on Tuesday. Even so, the e-retailer said it expects a record with roughly a 30% increase in sales at small businesses and sellers on the site.

Yelp(YELP) - Get Report was downgraded to underperform from market perform at Wells Fargo. The firm said the online reviews site would liekly struggle to meet long-term margin trends.

MetLife(MET) - Get Report was downgraded to hold with a $44 price target from buy at Deutsche Bank. Analysts said the company is leveraged to lower interest rates and lacks near-term catalysts.