Bank stocks finished up one of the best-performing weeks of the year Friday, as a global coordinated stimulus by the world's top central banks announced Wednesday injected some badly needed liquidity into the credit markets and signaled a willingness for future intervention if the going gets tougher.

The KBW Bank Index, an authoritative weighted index of U.S. banks, was up 10.57%. The Dow Jones Banks Titans 30 Index, which tracks some of the largest banks in the world, was up even more, some 13.4% for the week.

Some shares of individual banks, specially in Europe, went up even more.

The Royal Bank of Scotland, which is more than 80%-owned by the British government, was up 17.16% for the week to 21 pounds 53 pence. In the rush of the rally Wednesday, a trader even fat-fingered an order, paying nearly 170 pounds a share. Barclays ended the week 20.81 percent higher than where it began. Deutsche Bank, BNP Paribas, Societe Generale were all up similar percentage gains. Dutch behemoth ING Groep was up a stunning 27.16 percent for the week

Notably, banks not only surged on Wednesday, but were able to hold on to most of their gains on Thursday, despite the "hangover" from the previous day's party and the announcement of a major government lawsuit against the four largest U.S. lenders.

The rally in bank stocks continued Friday, as the wider financial was boosted by a report U.S. unemployment had fallen by 40 basis points.