"The question is how hard do people want to push stocks ... that's the tug of war going on in equity prices," Michael O'Rourke, chief market strategist at JonesTrading, in Greenwich, Connecticut, told Reuters.
Shares of ViroPharma soared, last up 25.5 per cent to US$49.42, after Dublin-based Shire agreed to buy the company, which makes drugs to treat rare diseases, for US$4.2 billion. Shares of Shire gained 0.9 per cent in London.
"Usually it's better to be the acquired than the acquirer, but the market seems to like these deals. Shire said the deal would help earnings in the first year though, which was somewhat comforting," Mike Ingram, analyst at BGC Partners, told Reuters.
The American government bonds market was closed today because of Veterans Day. The US Treasury is scheduled to auction US$70 billion of notes and bonds in the coming days.
In Europe, the Stoxx 600 Index added 0.3 per cent, as did the UK's FTSE 100 Index and Germany's DAX. France's CAC 40 climbed 0.7 per cent.
The euro strengthened against the greenback, rising 0.3 per cent. It also gained against the yen, last up 0.5 per cent. Investors judged the euro good value after the European Central Bank's surprise interest rate cut last week had pushed it to the lowest level in two months.
"Basically what we're telling our clients is 'don't chase the euro lower, look for a bounce to sell into'," Marc Chandler, the New York-based chief currency strategist at Brown Brothers Harriman & Co, told Bloomberg News.