Getty ImagesUS President Donald Trump's tariffs have ignited wildfires across global stock markets, but does that mean we are heading for a recession?
The first thing to stress is that what happens in the stock market is not the same as what happens in the economy - falling share prices do not always mean economic misery ahead.
But sometimes they do.
Very large falls in stock market values, like these, mean there has been a fundamental reappraisal of future profits for the companies that make up the stock markets of the world.
What markets quite reasonably expect is that increased tariffs will mean that costs will rise and profits will fall.
That doesn't mean that a recession is inevitable but the chances are clearly much higher than they were before Trump announced the most severe and wide-ranging tariffs seen in a century.
An economy is defined as being in recession when the total of everything we and the government spend or export shrinks for two successive three-month periods.
Between October and December last year, the UK economy grew a tiny 0.1% and the latest monthly data showed it shrank by the same amount in January.
The first estimate of how the UK economy fared in February will be released this coming Friday.
So, we are a long way off being able to tell whether we have hit that definition.
However, in the bloodbath of stock market falls, there are some particularly gory and worrying casualties.
Banks are often seen as proxies for economies. As one well respected market watcher told me today: "The thing that made me catch my breath was the fall in the banks."
HSBC and Standard Chartered - which operate at the intersection of international trade between east and west - were both down more than 10% overnight before recovering some ground.
Other warning signs are not on stock markets but commodity exchanges.
Copper and oil prices are considered barometers of global economic health.
Both have fallen more than 15% since Trump dropped his tariff bombshell.
There haven't been many truly global recessions.
The 1930s, the aftermath of the Great Financial Crisis and the panic around the pandemic are three rare examples of when we saw synchronised downturns in major economies.
It is still considered unlikely that we would see something on that scale this time but the chances of recession in the US, UK and European Union have been significantly upgraded by most economic analysts.
On the plus side for UK Chancellor Rachel Reeves, the government's borrowing costs are likely to dip by around £5bn to £6bn a year as investors flock to the relative safety of government bonds.
But that will be more than offset by hits to government tax receipts if and when the economy as a whole goes into reverse.
