The recent decline in the value of global stocks is down to deteriorating economic data, one market analyst has said.

Paul Sommerville, of Sommerville Advisory Markets, said analysts were beginning to question the narrative that the US economy was stronger than elsewhere.

"The ISM data came out in the US on Wednesday and it was the weakest in a decade. That's when we saw the start of the selling pressure. We're seeing signs that what's happening in the rest of the world is happening in the US," Mr Sommerville said.

The data out of Europe has been looking weak for some months now. Germany and the UK have both had one quarter of contraction. Two back to back three month periods of pullback is a technical recession.

The central banks in the US and Europe have announced interest rate cuts to shore up their economies and the ECB has said it will restart its policy of buying bonds.

The US Federal Reserve is coming under pressure to cut interest rates again.

"They cut rates in September and they'll probably cut again in October. They're certainly under pressure to cut," Paul Sommerville said.

One of the stock indices hardest hit in recent days was the FTSE in London. As well as posting four straight days of losses, it had its biggest one day fall in over three years on Wednesday.

"It has nothing to do with Brexit," Mr Sommerville said.

"The FTSE has been holding up because sterling has been falling in value. The stock market is now falling because of the US data. Traders were not expecting that and big companies get hit when that happens."

Further volatility and fluctuations are to be expected, he said.

"We could see some selling pressure in the US at the very least," he concluded.