If you define it as a 20% fall from highs, a bear market has emerged in the emerging markets (in US dollar terms) - but Europe is not quite there and everywhere else has so far seen a relatively modest correction.
Back in February, concerns about US inflation triggered a technical sell-off where the S&P 500 index fell by 10%. After falling now for five sessions in a row, the US is just 5% off its recent high. But the magnitude of some individual stock declines has spooked some investors so it is worthy of comment.
We have had several pullbacks in the past ten years since the financial crisis - all have been in some way justifiable and have left investors feeling bruised and nervous.
But markets by their nature settle down to find an equilibrium where the positive and negative forces are back in balance, and this normally happens quite quickly.
However, this decline is somewhat different from the February fall, which was really just a strange type of stop-loss tailspin that hit specialised ETFs in particular.
October's decline is being blamed on a spike in US bond yields but the underlying causes go a bit beyond that. This is an issue that is centred around the US (even if, as is often the case in times like this, other markets have felt the pressure more keenly).
Consider what has happened to US interest rates this year. The Federal Reserve's benchmark rate has been raised from 1.50% to 2.25% and 10-year bond yields have risen a similar amount from 2.40% to around 3.15%.
The current correction is largely a spasmodic adjustment by equities to higher rates and ostensibly tighter monetary conditions in the US.
Meanwhile the US economy is really very strong - it grew at an annualised rate of 4.2% in the second quarter.
Likewise, US corporate earnings have surprised even the most optimistic expectations from last year and this momentum is expected to have continued into the third quarter, with strategists looking for Q3 reported earnings per share in the US to be up around 25% over the same period last year.
That is a big jump, compared to a much more modest rise in the S&P 500 index of 9% over the past 12 months.
So in relation to prevailing company profits, US equities - and all other markets for that matter - are significantly cheaper today than they were a year ago.
But there are some genuine reasons for concern in relation to corporate earnings. There have been some telling profit warnings in recent weeks that have highlighted some growing challenges for companies. Take for example the recent comments from PPG, which makes paints and industrial coatings.
It cited issues with demand in China and from auto companies, input price increases, rising logistics costs and in general customers' reluctance to pay higher prices to compensate for these cost pressures.
The coming earnings results season will add more colour to this picture and point to those areas where - for now at least - profit margins may have peaked.
The general message, however, is that we should certainly not ignore current weakness in demand from China and cost inflation.
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