New York Governor Andrew Cuomo donned a face mask and rang the opening bell at the New York Stock Exchange yesterday.

This marked the partial reopening of the trading floor at 11 Wall Street, which had been shuttered since March 23 due to the coronavirus outbreak. 

It was a sign of survival of the financial heart of New York City, as the state has long been the epicentre of the US outbreak. 

The reopening comes in contrast to other major financial firms, including lenders and credit card companies, which have been more cautious, with most US staff working remotely. 

But it was hardly business as usual, with floor capacity down by 75% to help with social distancing, Plexiglas separators between trading pods, and other measures to reduce chances of an outbreak. 

"When we paused for the past two months, we took the opportunity to learn a lot about this virus, and what we learned is how to protect ourselves," NYSE President Stacey Cunningham said. 

The 100 or so traders, regulatory and operational staff who headed into the building were told to avoid public transportation and were screened for signs of the virus at the door, where they had to sign a liability waiver. 

"As trading on this iconic floor recommences, New York is showing the nation that we will lead the lead way," said Cuomo, who has turned his attention to re-opening New York. 

Most of the NYSE's designated market makers, who oversee trading in the exchange's 2,200 listed companies, are still working from home, as are most exchange employees. 

The NYSE operates the last US stock-trading floor, and a raft of all-electronic competitors having eaten away at the Big Board's once-dominant market share. 

It operated almost seamlessly during its electronic-only trading period, even with record volumes, volatility, and a 37% rally on the benchmark S&P 500 index, which broke back through the 3,000 level yesterday, before dipping back below ahead of the market close. 

That operational performance has prompted rivals to question the utility of the floor, where stocks have traded since 1792.

The NYSE says recent data show less volatility and tighter bid-ask spreads for NYSE-listed stocks when floor brokers are present, saving investors millions of dollars a day.