NYSE Euronext's stock surged $8.20 to $32.25. The boost at IntercontinentalExchange was much more modest, with the stock rising $1.79, or just more than 1 percent, to $130.10. That signals traders think the proposed deal could be more beneficial to NYSE Euronext than to its potential buyer.
Even without the complications of the budget negotiations, the U.S. economy has been difficult to read, a pattern that continued Thursday.
The government said the U.S. economy grew at an annual rate of 3.1 percent over the summer, higher than the previous estimate of 2.7 percent. But growth is likely to slow in the current quarter and early next year.
The government also reported that the number of Americans applying for unemployment benefits rose last week, a disappointment after four straight weeks of declines. The four-week moving average of jobless claims, a less volatile measurement, fell.
The yield on the 10-year Treasury note was unchanged at 1.80 percent. World markets were also mixed. Major stock indexes in Britain and Japan edged lower, while France and China rose.
A slate of companies reported earnings, with varied results:
—Darden Restaurants, the parent of Olive Garden and Red Lobster, fell $1.34 to $45.47 after the company reported sharply lower profits. New ad campaigns meant to attract younger customers haven't done as well as the company hoped.
—Rite Aid, the drugstore chain, soared 16 percent, rising 17 cents to $1.21, after the company reported its first quarterly profit since 2007. The pharmacies filled more prescriptions, and an influx of generic drugs helped profitability.
—Scholastic slipped 50 cents to $28.79 after reporting lower profit and revenue, with demand fading for its popular "Hunger Games" trilogy.
—CarMax shot up 9 percent, rising $3.13 to $37.97, after reporting higher profit and revenue. Sales of used cars helped push results higher.