BOY, it's been a turbulent week for investors and non-investors alike. Just when it finally seemed safe to go back into the water, a financial version of Hurricane Katrina dumped a torrent.

Wall St plunged near enough to 1000 points in two days, despite - because of ? - Barack Obama's win; our own market went straight back below 4000; treasurer Wayne Swan announced he'd "lost" Peter Costello's budget surplus; and spent nearly two agonising minutes trying to find his own inflation forecast.

Even the "good news" was actually bad news - the Reserve Bank slashing interest rates by a bigger-than-expected 75 points. Uh-oh, governor Glenn Stevens can see some bad times arriving. And just to round things off, the biggest child care provider in Australia revealed it hadn't really learned its financial ABC. Just about the only island of some stability was Bart Cummings winning his 12th Melbourne Cup. But even that was only by a whisker. Literally.

The big and pretty basic message out of all this is that turbulence is going to be the default mode for investors for some time yet. And for the economy. That does not mean though, that you should just curl up under the figurative blanket. It is times like these that fortunes - big and small - are not just lost, but are also made. And for the vast bulk of us that are not fortune-hunters, the basic objective is to - prudently - chart an investment course through the turbulence, for at least the medium and preferably the long term.

As I wrote last week, you had to understand that the overall market could still go lower. After going up, it promptly proved the truth of that; and indeed that warning holds true at Friday's level. That there would be more white-knuckle days - even more bad nights out of New York. Again, we promptly got them. But while the broader news has got worse over the past week, it arguably reinforces my central point. That now is precisely the time to look through all the gloom.

Over the past year, the market has plunged even though the actual economy has remained in pretty good shape. Witness the jobs numbers on Thursday - true, unreliable and lagging as they are. And even more potently, your own personal - non-financial - circumstances. That's true even for America, abstracting for the property market where the sub-prime mess has wreaked havoc. The point is that the market plunge was pre-dating, even predicting, the real economic slowdown that is now spreading and deepening. In exactly the same way the market will predate/predict the economic recovery.

If you stay under that blanket, figuratively speaking, while the economic gloom spreads - or worse, wait until the economic sun is clearly shining again - the bird will have flown. It'll be like trying to get on Viewed as the horses are being pulled up post. As I wrote, the absolute fundamental point about the share market is that history tells us you lose more by missing out on the big upswings than from being caught in the big dumps.

Although obviously if you are wise and can time things exactly, be out of the market in a year like 2008; and get back in at precisely the point it turns. The second thing that has changed is that central bankers and governments are now throwing everything at the economic slowdown and financial turmoil. Our Reserve Bank cut by 75 points, the Bank of England cut its rate by double that, 150 points.

Even the conservative European Central Bank cut by 50 points. Swan, meanwhile, has spent the budget surplus, and whether he likes it or even knows it, will spend more. As the economy slows, the budget "automatic stabilisers" kick in. Spending rises and tax revenues slow. It is impossible to be confident about how all this will play out. Or how long it will take. History never quite repeats