When George Bush announced a $$145bn (£75bn) rescue package of tax breaks at the end of last week, it was supposed to inject confidence into the world's largest economy.

But instead it had the opposite effect.

Global stock markets got the jitters, hence the dramatic falls.

In London yesterday the City endured its darkest day since the nadir of 9/11.

That's not only bad news for individuals from Northern Ireland who have a portfolio of FTSE 100 shares, it's also bad news for those Ulster people who pay into pension funds. Pension funds, after all, are the stock market's biggest customer. If shares lose value, then the funds in turn lose value.

In a single session yesterday some £77bn was wiped off the value of the UK's biggest companies as the FTSE 100 index plummeted by 5.5%, closing 323.5 points lower at 5578.2.

And investors in London faced more turmoil today after a second session of dramatic declines across Asian markets overnight.

Japan's Nikkei index tumbled more than 4%, while Hong Kong's Hang Seng slumped 7% as panicking traders bailed out.

City watchers were braced for further losses today as markets in the US - closed for a public holiday yesterday - reacted to the global falls across other exchanges.

Yesterday's Footsie fall was the eighth consecutive day of losses. Since Christmas Eve, the FTSE has dropped by almost 1,000 points.

Last week the FTSE 100 index dipped beneath the 6,000 mark for the first time since the credit crunch began in August. And today analysts were predicting further falls.

The Footsie is in fact now at its lowest levels for 18 months.

The UK market was dragged down by the heavily weighted mining giants, as the market has been hit by fears of waning demand for metals.

Rio Tinto and BHP Billiton, recently in talks over a $$150bn merger, were the worst performers on the day, both shedding more than 10% of their value.

As the fear of recession looms, the banking sector tends to suffer. Royal Bank of Scotland, Ulster Bank's parent company, fell 8.17% to 342.75p, while Lloyds TSB was down 6.92% to 373.5p.

In the current climate any vaguely scary news appears to be pummelling the markets.

George Bush's economic rescue package to address the US sub-prime crisis has come too late, according to market experts.

And no-one believes the world's other major economies will remain unscathed as America plunges into an economic downturn.

For the world's biggest companies, recession in an export market as vital as the US can only spell trouble.

Poor economic data and corporate news, as well as an acceptance that the sub-prime mortgage fallout has further to go, has created the "highly distressed conditions for a global sell-off in equities", according to Martin Slaney, head of derivatives at GFT Global Markets.