Euroopa tippanalüütikud hindavad, et stabiilsuse taastumine aktsia- ja rahaturgudel võtab aega kuid. USA börsid jäävad tõenäoliselt suletuks veel mitmeks päevaks. Teatas BBC.
Järgnevalt Euroopa tippanalüütikute värsked hinnangud tekkinud olukorrale.
'This is a big blow,' said Hans Redeker, economist at BNP Paribas.
'It could take several months but the US will be ready to take action to rebuild confidence and there will be a military strike.'
The blow to US sentiment will impact Europe, Japan and the rest of the global economy but by how much is difficult to say, economists said.
'I wish I knew,' said Nick Parsons, chief currency strategist at Commerzbank in London.
'The scale and scope are so big, we are just trying to take it in. But there are bigger things at stake than profits and losses.'
The US economy has experienced a sharp economic slowdown this year but has been kept afloat by consumer spending and so far avoided a recession.
'It is not a good thing for consumer confidence or investor confidence,' said Mr Redeker.
'The US Federal Reserve will now cut interest rates by 50 basis points on 2 October and there could be another cut in the November,' he added.
The Federal Reserve has cut interest rates seven times this year to try and keep consumers spending.
But Friday"s higher-than-expected US jobless figures of 4.9% for August heightened recession fears on Wall Street because consumers could stop spending over fears for their jobs.
Big apple hurting
Over the past eight years, Mayor Rudolph Giuliani had changed the country"s financial capital into an economic powerhouse and restored confidence in safety using hardline tactics against street crime.
But New York City"s dynamic tourism trade had flattened, joblessness was rising and tax revenues were expected to fall.
Tuesday"s attack is likely to heighten those concerns.
Despite the US Fed"s interest-rate cuts, New York City"s economy has slowed, growing just 1.3% in the last quarter.
That was well above national growth of 0.7% but was down from 2.3% in the first quarter of the year, according to the city"s financial controller.