It never fails to amaze me how traders can shift from extreme pessimism to outrageous optimism on the slightest of rumours, and the most slender reeds of hope.

Stock markets soared in Asia and are roaring forward in Europe today, and are poised for major gains in the US (as of 9 am Eastern time).

After one of the worst market weeks of the year, and a slew of gloomy news last week, what has changed?

Nothing.  Really.  Oh yes, the Black Friday weekend sales in the U.S. were huge and broke records — but wasn’t that to be expected when retailers extended Black Friday by opening at Midnight on Thursday instead of 4 or 6 am, and opted for volume over profits by offering staggering discounts?  We won’t really know the story of US holiday retail for some weeks — when we learn whether Black Friday and Cyber Monday simply drove forward consumers who, being unusually tight on money were desperate for  bargains, and thus cannibalized from December sales volume, and whether the combination of higher volume and steep discounts led to higher or lower profit margins for the season.

And yes, there were rumours of a new European plan to be launched at meetings this week and next (but all the other meetings and plans were so helpful, right?)  There were even suggestions that the U.S. Federal Reserve could bail out Europe by using dollars to buy up European bonds — but I doubt that is wise; since some Eurobonds will be defaulted, and the risks and counterparty coverage remain unknown, that would just import more uncertainty into the US bond market, which is not what the world needs.

Meanwhile, interbank lending within Europe is frozen, interest rates are rising or remain at critical levels for Italy and Spain, and we still do not have a clear vision of what lies ahead for holders of Greek debt.  Europe is almost certainly heading for a recession, there is no sign of steady growth in the US, China is slowing down, and India is struggling with legal and succession issues.

But hey, today is Cyber-monday.  Let’s all go out and buy!