The local sharemarket ended another big day of reporting season in the red, as a slide in miners led by Rio Tinto offset a number of positive earnings surprises.

Ardent chief executive Deborah Thomas says she is "not going anywhere" and will work to restore the theme park operator to its former glory after the company sank to a $49.4 million loss for the December half following the fatal accident at its Dreamworld theme park in October.

Shares in listed real estate group McGrath took another hit on Thursday as it warned "challenging" market conditions were likely to continue after reporting a dive in half-year pro-forma profit.

"If the business doesn't grow, how are we going to employ more people?" asks restaurateur Mohammad Bhuiya after the Fair Work Commission excluded restaurants and cafes from its Sunday penalty rate cut.

Investa Office Fund has issued an earnings upgrade for the full-year of 3 per cent, based on improving fundamentals for the national office market.

Former treasury boss Ken Henry has backed the government's 10-year plan to cut the company tax rate, saying it should be done even sooner.

The Victorian government is demanding the operator of Australia's main electricity grid explain how the state came close to losing electricity during the recent extreme heatwave to ensure NSW avoided power outages, adding to calls for a wider inquiry.

The euro has plunged against the Aussie as traders position themselves around the "redenomination risk" circling the French election.

Shares claw back some early losses as investors take profits in the big miners, while the dollar takes a whack from soft business investment numbers.

Is Wall Street's spectacular record run supported by economic fundamentals, or an outbreak of exuberance? Barclays reckons it is the former, while fundies aren't so sure.