Reuters' chief markets correspondent Jamie McGeever tweets:

Sterling's been on a rollercoaster this morning - dropping below $1.18 in a "flash crash" during Asian trading, coming back up above $1.24, and now it's on the slide again.

One pound is currently trading at $1.2253, down more than three cents on the day.

It's screeching downwards against the euro too, falling 2.5% to just above €1.10.

Image source, Getty Images

Britain's trade gap widened in August, despite hopes that a weaker pound had been boosting exports in the wake of the Brexit vote. 

The Office for National Statistics said, external the UK's deficit on trade in goods and services hit £4.7bn in August, widening by £2.5bn from July. Imports rose by £2.6bn, while exports only grew by £100m. 

Liam Fox, the international trade secretary, said: "While some sectors continue to perform well, there is still some way to go to ensure that we are exporting as much as we could and should do."

The head of research at financial services firm, the Resolution Group, tweets:

Image source, Getty Images

Norway's $882bn sovereign wealth fund, the world's biggest, returned a profit in the third quarter thanks to strong stock markets. The fund earned a return of 4% in the quarter, or 240 billion Norwegian crowns (£23.8bn) - better than the 1.3% profit for the three months to June. 

The fund invests the proceeds from Norway's oil and gas revenues in foreign stocks, bonds and real estate. Its value corresponds to about $170,000 for every Norwegian. 

The government withdrew 30bn Norwegian crowns during the quarter to pay for public expenses at a time of declining oil and gas revenues, compared with 24bn crowns in the second quarter.

This blog post, external on the machinations of sterling overnight will amuse some readers - but beware some fruity language if you're the sensitive type.

Here's a flavour: 

Image source, AFP

After wider losses triggered by the sterling "flash crash", Asian stock markets stabilised by the end of the trading day.

Tokyo's Nikkei 225 closed down 0.2%, Hong Kong's Hang Seng slipped 0.4%, while Sydney's ASX 200 ended 0.3% lower and Seoul's Kospi shed 0.6%. 

Mainland Chinese markets have been closed for the week-long National Day holiday. 

The flash crash in the pound - which is being blamed on a computerised trade reacting to French president Francois Hollande demanding "tough Brexit negotiations" - shows how careful politicians need to be, according to one trader.

"If Hollande wants negotiations for hard Brexit, fair enough; but he should be careful what he wishes for," says Michael Hewson of CMC Markets. 

EU leaders are "sitting on a bed of nitroglycerin" because the economic fallout from Brexit is most likely to affect the banking sector and Europe's banks are more vulnerable than those in the UK.

"For politicians to start sabre-rattling, they are ultimately doing harm to their own economies," he tells us.

The Bank of England is investigating the cause of a sharp fall in the value of the pound in overnight trading in Asia.

"The Bank is looking into last night's fall in sterling," the spokesman said. 

Traders have said they believed computer-initiated sell orders pushed the pound down steeply earlier on Friday which left the currency on track for its worst week since the Brexit vote in June.   

Today Programme
BBC Radio 4

Zac Goldsmith - the MP for Richmond Park in southwest London - says a third runway at Heathrow has no prospect of going ahead.

Kevin Peachey
Personal finance reporter

Image source, Thinkstock

A gap between the average age of first-time buyers in different parts of the UK has set in despite property price growth slowing, a lender has said.

The Halifax said that UK property prices rose by 5.8% in September compared with a year ago.

This offers some cheer to first-timers who faced annual rises in house prices of 10% six months ago.

Yet those buying in the priciest parts of the UK were typically seven years older than those in cheaper areas.

The Halifax said that the youngest first-time buyers were in Carlisle in Cumbria and Torfaen in south Wales where they bought at an average age of 27. The oldest were in Slough in Berkshire as well as Barnet and Ealing in London where the average age was 34.

Overall in the UK, the lender said the average first-time buyer was aged 30.

Most are likely to be looking for properties a lot cheaper than a £14m mansion that has just been sold in south London or a typically priced home in the UK which, according to the Halifax, now costs £214,024.

Today Programme
BBC Radio 4

Image source, PA

The chances that Theresa May will announce a third runway at Heathrow later this month are getting stronger by the day.

Sir Howard Davies, whose report last year recommended Heathrow expansion over Gatwick and other options, says the government appears to be close to a decision.

"I do think the stars are more aligned for a decision now than they have been for some time," he tells Today. "There's a very great need in a post-Brexit environment for the country to set a direction and for some new investments to occur."

Heathrow is the best for this because more than any other airport it links the UK to markets outside of Europe, Sir Howard adds.

He predicts the third runway could be operational by 2026, particularly as arguments against air quality - previously seen as Heathrow's key vulnerability - "are not as strong as some people think".

Financial Times journalist Katie Martin tweets a prediction from Citi analysts:

Image source, Getty Images

UK industrial output fell unexpectedly in August, partly due to oil field shutdowns, though there were some limited signs that the pound's fall since June's Brexit vote had boosted factory exports. 

The trade deficit also widened more than expected, jumping to £12.1bn in August from £9.5bn in July, smaller than first estimated, the Office for National Statistics said. 

Industrial output fell 0.4% month-on-month in August after a 0.1% increase in July, the ONS said. Economists had expected a 0.1% rise. 

The figures are likely to temper some of the optimism about how the UK economy has fared since the Brexit vote.

Business correspondent Theo Leggett tweets:

The Times consumer affairs correspondent Andrew Ellson tweets:

Shares in gambling stocks have taken a hit in early trading. Ladbrokes is down 2.4%, William Hill is 1.6% lower and Paddy Power Betfair is minus 1.3%.

Today Programme
BBC Radio 4

Image source, Getty Images

Jeremy Stretch, a currency analyst, points out the flash crash in the pound came in the twilight hours - between North America going home and Asia coming in.

While he says that overnight moves don't have too much significance, "what we shouldn't step away from is that sterling has been under pressure, not just this week but over the past three months", says Mr Stretch, head of FX strategy at CIBC.

It's very difficult to see the pound rallying much unless some of the rhetoric from the politicians is toned down, he tells Today.

Image source, Conservative Party

The pound’s slide is “not unwelcome”, according to international trade minister Mark Garnier.

Speaking in Hong Kong earlier today, he said sterling had “probably been too high anyway” against the euro and the US dollar - and was now correcting.

“Clearly it’s to do with the [Brexit] vote, but actually it’s not an unwelcome reaction. Sterling is probably about where it should be,” Mr Garnier told the South China Morning Post, external. “We’re just going through a relatively short period of volatility.”

Image source, Getty Images

In case you were wondering, the FT story, external that seems to have got the rogue algorithm hot under the collar was headlined "Hollande demands tough Brexit negotiations - French president seeks to avoid contagion and protect fundamental principles of single market".

At a dinner in Paris on Thursday night, Mr Hollande said: “The UK has decided to do a Brexit, I believe even a hard Brexit. Well, then we must go all the way through the UK’s willingness to leave the EU. We have to have this firmness.

“If not, we would jeopardise the fundamental principles of the EU. Other countries would want to leave the EU to get the supposed advantages without the obligations.”

FT reporter Lauren Fedor tweets: