Shock news that Britain had voted to leave the European Union hit European stock markets hard today, with London's FTSE 100 index recovering from early losses to close down 3.2%.
UK banking and construction shares were among the biggest fallers, with Lloyds Banking Group down 20%, while Barclays dropped by 15%. Airline stocks were also sharply lower, with shares in EasyJet down down 15%.
Aer Lingus owner IAG dropped over 20% after it said "it no longer expects to generate an absolute operating profit increase similar to 2015" due to a weaker than expected trading environment in the run up to the Brexit referendum.
The Frankfurt stock exchange suffered a 7% blow, while Paris slumped 8%, with Milan losing 12.5% and Madrid 12.4%.
What impact is Brexit having on the markets in mid-morning trade? @davidmurphyRTE assesses the current state of play pic.twitter.com/4VyUi8F2ce
— RTÉ Business (@RTEbusiness) June 24, 2016
At home, the Dublin market closed down 7.74%, after falling as much as 16% in earlier trade.
Among the big falls on the ISEQ index today were the banking stocks, with Bank of Ireland down 20% while Permanent TSB was down almost 20%.
Shares in Ryanair also dropped nearly 11% while Dalata Hotel Group was down by 14.4%.
The ISEQ had lost more than 16% just 15 minutes into trade, but has rallied slightly since #EUref pic.twitter.com/jGxlRwKI0Q
— RTÉ Business (@RTEbusiness) June 24, 2016
In the US, stocks have also fallen sharply, with the Dow Jones dropping as much as 538 points.
The S&P 500 index and Dow are on track for their biggest one-day percentage drop since September, while the Nasdaq is headed for its worst day since January.
All three indexes are set to post their second weekly decline in a row.
Banks stocks, which had risen strongly this week in anticipation that Britain would stay in the EU, were among the biggest losers.
Citigroup was down 8% and Morgan Stanley 9.4%, while Bank of America, JPMorgan and Goldman Sachs dropped by between 5 and 6%.
Billions were wiped from share values in earlier Asian trade as Japan's Nikkei index slumped 7.9%. Shares in Hong Kong closed 4.4% lower while Australian stock markets fell over 3%.
Such a body blow to global confidence could well prevent the US Federal Reserve from raising interest rates as planned this year, and might even provoke a new round of emergency policy easing from all the major central banks.
Risk assets were most affected as investors fled to the traditional safe-harbours of top-rated government debt, Japanese yen and gold.
Meanwhile, early on sterling sank a staggering 10.1% to $1.3387, having carved out a range of $1.3228 to $1.5022.
The fall was even larger than during the global financial crisis and the currency was moving two or three cents in the blink of an eye.
The shockwaves affected all asset classes and regions.
The safe-haven yen sprang higher to stand at 101.34 per dollar, having been as low as 106.81 at one stage. The dollar decline of 4% was the largest since 1998.
Financial markets have been racked for months by worries about what Brexit, or a British exit from the European Union, would mean for Europe's stability.