Midday Report: Services Sector Expands; U.S. Stocks, Oil Fluctuate

U.S. stocks were in flux as uncertainty over how and when the UK will exit from the EU kept traders nervous. Biotech gave the Nasdaq a boost, while wild swings in crude oil kept the energy sector in the red. Growth in the U.S. services sector expanded in June at its fastest pace in seven months, according to the ISM Non-Manufacturing Index. Both the employment index and the business activity index rose last month. American Airlines (AAL) - Get Report weighed on its peers after Credit Suisse hit it with a two-notch downgrade to UNDER PERFORM. Analysts said industry unit revenue growth will likely continue to disappoint. Gold producers jumped as investors sought safe-haven assets amid the uncertainty of the Brexit situation. Prices hit their highest level in 28 months earlier in the session.