Stocks drop for 2nd day as Yellen speech looms

U.S. stocks ended lower Thursday as investors await a key speech on monetary policy tomorrow from the head of the U.S. Federal Reserve.

The Dow Jones industrial average ended down 33 points, or 0.2%. The broader Standard & Poor's 500 stock index lost 0.1% lower and the Nasdaq composite finished down 0.1%.

Low rates have been a key underpinning of the bullish thesis for stocks -- which continue to hover near all-time highs. Wall Street will be closely listening Friday to Fed Chair Janet Yellen's comments related to the timetable for coming interest rate hikes at a high-profile symposium in Jackson Hole, Wyo. The Fed has held interest rates steady this year, after hiking rates off zero in December for the first time in nearly a decade.

All three major U.S. stock indexes remain within striking distance of their record closing highs set earlier this month.

The yield on the 10-year U.S. Treasury note ticked up to 1.57% in early trading from 1.56% Wednesday ahead of Yellen's key speech on monetary policy tomorrow.

In economic news, durable goods orders for long-lasting products like refrigerators and commercial aircraft, jumped 4.4% in July, topping expectations.

On the individual stock front, shares of drugmaker Mylan (MYL) fell 0.7% after the company responded to the controversy surrounding a sharp price hike on its EpiPen -- a life-saving allergy shot -- by offering consumers a rebate in the form of a savings coupon that the company says will cut the cost of the drug in half.

Shares of high-end retailer Tiffany (TIF) ended 6.4% higher after it posted earnings per share that topped quarterly expectations and reaffirmed its guidance, despite a 8% drop in sales at stores.

Stocks in Europe were under pressure after a reading on Germany's economy came in weak. The broad Stoxx Europe 600 was down 0.8%, the DAX index in Germany was off 0.9% and the CAC 40 in Paris was 0.7% lower.