Shares in HBOS, Lloyds TSB and Barclays climbed more than 14%, 9% and 8% respectively on Friday after the FSA raised the savings guarantee in the event of a bank going bust.
Investors took a cautious approach when London markets opened, with the FTSE 100 down 28.4 points (0.58%) to 4,841.
The Dow Jones Industrial Average has taken an unexpected fall in early trading, slumping almost 2% to 10.622.15, despite a confirmed $750bn bail-out of the nation's bad debt.
A near 20% jump in the share price of Halifax Bank of Scotland (HBOS) helped steer the FTSE clear of the 5,000 mark on Thursday.
Shares in HBOS and Lloyds TSB staged a late rally fuelling speculation the buyout deal is back on track.
Shares in the FTSE 100 saw a tumultuous but mostly positive morning after news of an alternative to the $700bn bail-out emerged in the US.
London and European markets calmed down in mid-morning trading after the sharp opening decline driven by the rejection of the US $700bn bank bail-out plan.
The UK economy is set for more than a year of recession or stagnation, with only slow recovery thereafter, according to the centre for economics and business research (cebr).
Profitability and business volumes in the UK financial services sector fell at record rates in the three months to early September, according to the results of the latest CBI/PwC survey.
The FTSE100 has plunged under 5000 again this morning as investors retreat from financial stocks in the wake of the Government's Bradford & Bingley nationalisation.