NYSE Arca, the trading venue at the New York Stock Exchange which houses its listings of exchange traded funds, was hit with a technical issue that affected the closing of securities.
The problem occurred ahead of the so-called closing auction. While stocks and ETFs can trade at different exchanges notwithstanding where they list, typically they revert to the listing exchange for the closing price.
NYSE has not said which securities were affected. All outstanding orders at the time were cancelled.
For securities that didn’t have a closing auction, the office closing prices will be based on the volume weighted average price for trades in the last five minutes of regular trading hours, including the closing auctions on all markets.
If there were no trades in that time period, the official closing price will be based on the consolidated last sale during regulation trading hours and if that is not available, the closing price will be the official closing price of the previous session on the primary exchange.
As of September 2016, NYSE Arca’s listed exchange traded products had over $2.2tn in assets under management, representing over 92 per cent of all US listed ETPs.