New Zealand's sharemarket has tumbled in one of the biggest daily drops that traders have ever seen.
Every single stock bar one on the benchmark S&P/NZX50 index was in the red.
The index itself fell 3.64 per cent to 8721.2.
Rickey Ward, New Zealand equity manager at JB Were, said of the local sharemarket drop:
"It's one of the biggest one-day falls ever, but not the biggest. It's certainly the biggest move for some time.
"We don't have moves like this every day, not for a very long time."
The share plunge hit some of the New Zealand market's biggest companies, shaving about $420 million off the total market value of Fisher & Paykel Healthcare, $850m from a2 Milk and $408m from Auckland International Airport.
Ward said growth stocks like a2 Milk, which had played a big part in the share market's rally over the last year, had acted to drive the market down.
A2 Milk's share price fell by $1.17 to $9.04 — a decline of 11.4 per cent.
However, Ward said it felt like a market was going through a "reset" after what has been a very strong, record-breaking run.
"This feels more like a reset. Corporates are still growing their earnings — in the US in particular. The underlying outlook still remains reasonably sound."
He said the problem had been that share prices had been running ahead of company's earnings prospects, particularly for the growth companies.
The local slide followed some Wall St indexes falling by as much as 3.2 per cent overnight Wednesday.
Technology stocks led the way.
Apple and Amazon, the two most valuable companies in the S&P 500, each had their worst day in two and a half years. Apple slipped by 4.6 per cent while Amazon lost 6.2 per cent.
The drop was largely due to the US Federal Reserve's track for higher interest rates pushing yields on US government bonds higher.
The yield on US 10-year Treasuries has been at a seven-year high and closed at 3.17 per cent.
In contrast, New Zealand's 10-year Government bond recently traded at a yield of 2.67 per cent.
Sentiment also has been dampened by the spreading US-Chinese tariff fight over Beijing's technology policy.
The International Monetary Fund also cut its outlook for global growth this week, citing interest rates and trade tensions.
Leighton Roberts, chief operating officer and co-founder of Sharesies, urged New Zealand investors not to panic.
"Most New Zealanders will be seeing this in their KiwiSaver accounts but it's a matter of realising that is long-term money.
"For us we are just reiterating don't panic. If you are confident that you are diversified and in for the long-term it is a time for buying rather than selling.
"Stay the course, you still own the same companies you owned yesterday."
Roberts predicted volatility in the markets would continue but said that was more a return to normal levels after a low level of volatility.
"We have seen unprecedented levels of low volatility."
Roberts described the fall as a slight correction and said he hoped markets would recover similar to what had happened in February and March this year after a dip in the markets also sparked by rising bond yields.
Asian markets were broadly lower on Thursday as they too followed Wall St slump.
Japan's benchmark fell by an unusually wide margin of 3.9 per cent and China's main index lost 4.3 per cent.
Markets in Hong Kong, South Korea, Australia and Southeast Asia recorded similar declines.
Why has this happened?
The local market took its lead from the US, after shares there fell by 3.2 per cent — as measured by the Dow Jones Industrial Average. Shares on many Asian markets also fell sharply.
What's America's problem?
One concern is President Trump's trade war with China. Another problem is rising interest rates. The US central bank — the Federal Reserve — has been lifting rates and plans to keep doing so, as it tries to avoid rising inflation. Both higher rates and trade disruption could choke off US economic growth.
What does it mean?
For KiwiSavers, the fall will put at least a short-term dent in earnings, and it could also hit the NZ Super Fund's returns.
Is this the start of something bigger?
No-one knows. There are plenty of concerns about international economic growth, but there are also optimists about shares' longer-term outlook.