US Stocks gain 2% for the week, despite slow Friday (ext)

NEW YORK (CNNMoney) -- U.S. investors were unwilling to place any big bets Friday, as key Greek debt talks remain unresolved.

Despite that, all three indexes still closed out the week more than 2% higher on robust economic data and strong earnings.

The 2012 rally has left some investors wondering whether it's sustainable. "People have to be cognizant that the more expensive the market is, the harder it is to move the needle," said Uri Landesman, president of the hedge fund Platinum Partners.

Investors continue to fear repercussions from the European debt crisis, particularly the prospect that Greece may end up defaulting in a disorderly fashion. A deal on restructuring Greek debt remained elusive on Thursday, but talks continue Friday.

The dollar rose against the euro, the British pound and the Japanese yen.

Oil for February delivery slipped $2.28 to $98.11 a barrel. Oil for March delivery, which becomes the active contract at the close of trade Friday, lost $2.21 to $99.33.

Gold futures for February delivery added $9.50 to $1,664.00 an ounce.