On Wall Street last night shares enjoyed their second largest percentage rise ever, soaring by  10.8 per cent or  889 points to 9065.12.
 
That is a massive rise. So is this the end of the great financial crash? The beginning of the end? Or just a lull in the storm?
 
The encouraging news is that this global rally has been prompted by expectations of a big cut in interest rates by the US Federal Reserve later today and by the prospect of cuts here in Britain, too, when the Monetary Policy Committee meets next week (how exasperatingly unhurried it all is at the Bank of England - never let a screaming recession get in the way of the monthly timetable of its deliberations).
 
However, since the likelihood of another Fed rate cut - and its timing - has been known for weeks, it is odd that it is only now that that the markets have taken this likelihood on board.
 
Interest rates will help in due course - though it takes time - between a year and 18 months typically - for the full effects to work through.
 
The worry is that the world's biggest central bank is now getting down to the last rounds of ammunition. There is a historical reluctance to cut rates below one per cent. So the Fed chairman Ben Bernanke really is in the Last Chance Saloon.
 
But there's a deeper worry. And its has to do with previous patterns of stock market falls.  Chartists - the school of investment analysis based on the behaviour of  prices and indices - have long believed there is a pattern to stock market rises and falls. The biggest school follows the Elliott Wave after work by Ralph Elliott published in the 1940s.
 
Very broadly, chartists argue that  markets do not go down in one straight plunge but in a series of  jagged downward lunges - typically three downward legs and two 'corrective' upward legs. And on current readings we may now be enjoying a secondary correction before a further fall to a new low.
 
The first downward leg took the FTSE100 Index from 6716.7 on July 13 last year to 5414.4 on March 17 this year.
 
Then there was an 18 per cent correction to 6376.5 reached on May 19.
 
The market then suffered its second down wave, falling to below 3,800 earlier this week.  We could now be seeing a short upward correction before the market turns down again for its third and final down wave to a new low. This could take the FTSE100 to 2,800-3,200, or possibly all the way down to 1,800-2,200.
 
As for Wall Street and its second highest upward move ever last night, I checked back to find out when the biggest ever percentage rise had been.
 
The date was not reassuring.
 
On October 30 1929, the day after the epochal crash, the Dow Jones Index rallied by 12.3 per cent. There was a three month rally which saw the market gain 45 per cent. It then went nowhere for three years and finally bottomed out on March 15 1933, when it at last began a sustained rally. And it did not go above and stay above its 1929 peak until 1953 - in other words, a full recovery took 24 years.
 
I'm not saying history will repeat itself. It never does on stock markets, otherwise movements would be entirely predictable and we would all now be living in villas on Seven Mile Beach, Grand Cayman. But "mind your eye" on those bounces.