European shares surged and the Greek stock market jumped 8% while the borrowing costs of Italy, Spain, and Portugal — the countries most likely to be hit if Greece heads for the eurozone exit — fell sharply.

Disappointing earnings news and a slump in bank stocks tugged the US stock market down yesterday, giving major indexes their first three-day drop since June.

World stocks rose more than 1% yesterday and the euro gained amid optimism the world’s central banks will provide more economic stimulus as the eurozone debt crisis worsens.

US stocks ended a rough week with slight gains today after Libyan government forces declared a ceasefire and a group of the world’s seven largest countries announced a plan to bring the yen down from historic highs.

US stocks closed slightly lower today as investors’ pessimistic view of the economy deepened.