American biotech stocks have fallen around 5 percent in value following a single tweet from presidential candidate Hillary Clinton.
She tweeted that she planned to do something about price gouging by pharmaceutical companies.
The tweet was sent out after reports that one company has raised the price for one of its drugs from US$13.50 to $750. That is an increase of 5500 percent (an increase in New Zealand dollars from $21.37 to $1187).
The drug, called Daraprim, is used to treat a parasitic infection called toxoplasmosis. The infection can cause life-threatening problems for babies born to women who become infected during pregnancy, and also for people with compromised immune systems.
The drug is 62 years old. In August it was bought by a company called Turing Pharmaceuticals, a start-up operated by a former hedge fund manager.
Turing immediately raised the price, meaning patients face hundreds of thousands of dollars a year in treatment costs.
There has been growing concern about the cost of new drugs. But Turing's actions have cast a spotlight on the issue of the rising cost of many older drugs.
The iShares Nasdaq biotechnology ETF (IBB) closed down 4.48 percent.
The wider market managed to clamber out of negative territory, despite what turned out to be the biotech sector's worst day of the year.
The Dow Jones Industrial Average gained 0.72 percent, or 117 points.
The broader S&P500 rose 0.46 percent, or 8 points.
Blue chip drug stocks Merck, Pfizer and Johnson & Johnson, all lost ground.
The Nasdaq, which includes many biotech companies, was up a very modest 0.04 percent, or 1.7 points.
The world's top selling car maker is embroiled in a financial and public relations disaster.
Shares in VW have tumbled following reports the company rigged US emissions tests for half a million diesel vehicles.
The company's stock price lost 18 percent on the German market, wiping 13 billion euros (NZ$23 billion) from the company's value.
VW is accused of installing software that can tell the car's computer when it is being tested for emissions standards. Those standards are required under the US Clean Air Act.
VW has halted US sales of the affected vehicles and pledged to cooperate with regulators in an investigation that could potentially lead to US$18 billion in fines against the company.
The company could face US$20 billion (NZ$31 billion) in fines from US authorities and its chief executive Martin Winterkorn has apologised, saying VW "had broken the trust of our customers and the public".
The German government has called for an urgent probe into whether VW and other car companies might have manipulated tests in Germany.
Porsche, a subsidiary of VW, lost 17 percent of its value.
The scandal has also prompted a sell-off of other car markers.
France's Renault SA was down 3.2 percent, Daimler AG (owner of Mercedes-Benz) lost 1.4 percent and BMW AG fell 1.5 percent.
Tech giant Apple is forging ahead with its plans to get into the car market.
The Wall Street Journal is reporting that Apple has set a shipment date of 2019 for its electric car.
Six hundred people are employed on what is being called Project Titan by Apple. But Apple wants to triple staff numbers as it accelerates development of the car.
Apple shares rose 1.55 percent.
The latest consumer confidence figures could spell trouble for New Zealand retailers.
Confidence has fallen to a three-year low in the latest Westpac McDermott Miller survey.
The survey's confidence index fell to 106 in the September quarter, its lowest level since September 2012. Anything above 100 indicates that optimists still outweigh pessimists. But the figure is below the survey's long term average.
The near term outlook is not as positive. The net percentage expecting mainly good economic times for the year ahead fell from 4.8 percent positive in the last survey to 15 percent negative this time. It is the first time the measure has dropped into pessimism since December 2012.
The reasons for the pessimism vary between the cities and rural areas.
"The former are expecting bad economic times because of 'ineffective government economic policy' (29 percent), followed by 'low dairy prices' (23 percent)," says McDermott Miller's Richard Miller.
"A net 25 percent of rural consumers expect bad times, with some 39 percent blaming 'low dairy prices' and 30 percent pointing to ineffective government policy'."
There were also more modest declines in respondents' longer-term economic outlook and their assessment of their own financial situation.
The net percentage expecting mainly good economic times over the next five years fell from 24.3 percent to 24.1 percent, while the net percentage expecting their own finances to improve over the year ahead fell from 5.9 percent to 4.6 percent.
The net percentage saying their financial situation had improved over the past year fell from 1.4 percent to negative 3.0 percent.
People are becoming increasingly unsure this is a good time to buy major household items. The net percentage saying that now is a good time to buy a major household item fell from 28.8 percent to 19.5 percent.
"The main reason given by some 26 percent is 'they have no money to spend'. When this factor is put alongside negative sentiment over New Zealand's short-term economic prospects, a slowing down in growth of retail sales is likely in the months ahead," says Mr Miller.
Over the next six months Westpac expects the dairy industry to remain under pressure, unemployment to rise, and tax and lending restrictions to take some of the steam out of the Auckland housing market. It says consumer confidence could well fall further, and spending is likely to continue to slow.
The survey found that confidence has fallen hardest among higher-income households, among middle-aged and older households, and among men rather than women. The authors of the survey say they are not quite sure why men have become relatively more downbeat. But "we suspect that concerns around asset values and investment returns have weighed heavily among the better-off and older consumers".
The New Zealand dollar has not had a good start to the week.
The Kiwi was trading at US 63.17 at 8am, down 1.2 percent from yesterday.
It was down half a percent against the Australian dollar at 88.56 cents.
The Kiwi had fallen 1 percent against the pound, trading at 40.74 pence.
It was 56.44 Euro cents and 76.12 Yen.