The roll-out of a new program to limit wild price swings in publicly traded securities triggered dozens of trading halts on Monday as highly illiquid names were phased into the program.
About 45 exchange-traded products (ETPs) were halted by midday on NYSE Arca, a unit of exchange operator NYSE Euronext, according to trading information provided by exchange operator Nasdaq OMX Group Inc.
About 570 securities were rolled out on Monday as part of the second stage of the "Limit UP, Limit Down" program approved by the Securities and Exchange Commission last year.
A trading halt is triggered if a price rises or falls more than 5 percent over a 5 minute span for the most heavily traded shares, composed mostly of securities with a market cap of about $1.8 billion or larger.
The second phase of the program, with the price band widening to 10 percent to trigger a halt, includes more illiquid stocks, some of which do not trade on many days.
A NYSE Euronext spokeswoman said the new program was in its initial phase of an expanded universe of ETPs. She said the exchange was working within established guidelines, and would explore the trading limits with regulators and other exchanges.
NYSE Arca accounts for about 90 percent of ETPs, a reason why so many of the trading halts occurred on its platform.
The spread between the bid and offer price of an illiquid ETP can be so wide it will readily trigger a trading halt under the new program, said Dennis Dick, a proprietary trader in Detroit at Las Vegas-based Bright Trading LLC.
"In some cases even a small-sized order could be enough to cause the price band threshold to be exceeded, which would trigger a trading pause," Dick added.