Many New Zealanders will still feel rattled by the 7.8 magnitude earthquake that woke the nation in the first few minutes of this week. On the NZX, however, the tremors were barely felt - supporting the theory that markets shake off big shocks.

Not only did investors' nerves hold up, but our local exchange rallied by 0.6 per cent on Monday, and by almost 2 per cent since the start of the week. The S&P/NX50 was down 0.07 per cent early this afternoon at 6820 points after being in positive territory for much of the morning.

Although the index shrugged off the disaster, the expected fallout from Monday's bedlam had an immediate impact on the fortunes of companies such as Fletcher Building and Tower.

The rebuild work that investors expect to come Fletcher Building's way pushed the construction company's shares up 2.5 per cent to $10.38 on Monday morning and even more as the week went on, reaching $10.80 in trading across the rest of the week so far.

Tower shares fell 9.4 per cent after the market opened on Monday and are trading this afternoon at 77.5c - down from last week's close of 85c.

The week's trading helped cement the two companies' positions as the best and worst performers on S&P/NX50 Gross Index. Fletcher Building shares have surged 46.94 per cent since the start of the year while Tower shares have slumped 59.21 per cent.

Despite the havoc and upheaval disasters cause for people and communities, stock markets have proved resilient over the years.

On the day of the February 2010 Canterbury earthquake that killed 195 people, the NZX50 closed down 0.7 per cent, but recovered this ground within a week.

During Hurricane Katrina - one of the worst disasters in US history - the S&P 500 index enjoyed an eight-day 3 per cent rally, according to Nasdaq.com.

And when an earthquake struck off the west coast of Sumatra on Boxing Day, 2004, triggering tsunamis that killed more than 200,000 people, US markets didn't even appear to even register the event, Nasdaq.com said.

"A low came 20 trading days later when the S&P [500] had corrected 3.8 per cent. It went on to rally as much as 35 per cent thereafter," the website said.

An exception was the 2011 Japanese earthquake, which caused widespread devastation as well as a radiation leak at the Fukushima nuclear power plant.

The Nikkei 225 index fell 17.5 per cent in the days following the disaster and didn't recover to pre-quake levels for more than a year.

TRUMP SLUMP

While Tiffany Trump's stocks may be rising in light of her father's victory in the presidential election, her namesake might suffer from its close association with the real estate mogul and his home.

US analyst Oliver Chen has warned that the proximity of Tiffany & Co's flagship store on Fifth Avenue in New York to Trump Tower - their main entrances are next door to each other - could adversely affect the jeweller's sales in the short term, thanks to protests in the surrounding area, as well as the street closures and extra security measures that would accompany any presidential visit.

The analyst estimated that traffic at this location, the company's biggest in the world, could be cut in half, and trimmed his fourth quarter earnings per share forecast by 3USc.

"There's no way to sugarcoat this, the big worry is what will happen over the next few months," Chen said. "They are very important weeks before Christmas."

Nonetheless, the analyst has a "outperform" rating and US$90 ($127) price target on the stock, which traded this week at US$75.76.

"The entrance to the Tiffany's flagship store on Fifth Avenue was not open when we checked," added Macquarie Capital Markets analyst Laurent Vasilescu, who also voiced concerns about the potential hit to the firm's top-line performance in the fourth quarter.

A 10 per cent decline in same-store sales at Tiffany's crown jewel location translates into more than a 0.8 percentage point hit to worldwide same-store sales, Vasilescu reckons. If President-elect Donald Trump continues to visit Fifth Avenue and 57th Street frequently after he's sworn in, this drag on sales at the flagship could prove more enduring.

The stock is roughly flat since election day, but has suffered a substantial decline over the past two sessions.

Public displays of opposition to Trump and the potential for terrorist attacks and other threats have resulted in a large-scale police presence at Trump Tower since November 8, and balancing commercial and security interests will pose a difficult challenge heading into the holiday shopping season.

A spokesperson for Tiffany's said the company is in frequent communication with the Secret Service and New York Police Department on matters pertaining to safety and security in the area, and directed visitors to its 57th Street entrance.

- staff reporter, Bloomberg