A Donald Trump election victory and corresponding rise in US bond yields would be a "worst case scenario" for the local sharemarket, according to JBWere New Zealand.
And the investment firm is warning that the race for the White House remains close, despite recent controversy over the Republican nominee's relations with women.
"We believe markets are under-pricing the risk of a Trump upset next month," JBWere investment strategist Bernard Doyle said in report released on Friday.
Hillary Clinton is ahead in the polls and a win by the Democratic candidate on November 8 would be viewed as a positive outcome by financial markets.
"Our best judgement is a 5 to 10 per cent global equity pullback would be likely in the event of a Trump surprise," Doyle said.
He said the New Zealand sharemarket could be insulated, to some extent, from the fallout.
But it would be far from immune.
"Our worst case scenario would be a Trump victory with an attendant rise in US bond yields," Doyle said.
"This would hit New Zealand equities directly through our interest rate sensitivity and indirectly through fears of a global trade war."
Doyle told the Business Herald that stimulatory policies promised by Trump, such as cutting taxes and boosting government spending, were likely to increase the speed with which US interest rates would rise.
"That's where the New Zealand equity market would be facing a headwind because we've benefited from a falling interest rate environment and the fact that we're a nice, stable dividend payer."
He said investors in US treasuries would also expect higher returns on their investment as a result of the risks associated with increased government borrowing likely to occur under a Trump presidency.
Many traders are already questioning how long an extended bull-run in equities can be sustained, particularly if US interests rates begin rising and bond yields move higher, making stocks less attractive.
The US Federal Reserve is widely expected to hike rates for the first time in December - which would be the first increase since the same month in 2015 - followed by further tightening in 2017.
The New Zealand equity market, which has a reputation as a solid source of dividends, has benefited from low interest rates and the global search for yield, which has driven the S&P/NZX 50 index to record levels.
But the NZX has underperformed its peers in recent weeks as high dividend-paying stocks have fallen out of favour.
The S&P/NZX 50 has fallen roughly 6 per cent from the record high of 7571.105 it reached on September 7, but remains up around 12 per cent in the year to date.