
Held at the Opening and Functions
A trading halt in general is a temporary suspension in the trading of a particular security on one or more exchanges, usually in anticipation of a news announcement or to correct an order imbalance or because a circuit breaks has been triggered (discussed below). Sometimes the official open of exchange trading on a security will be delayed as the DMM balances the orders on their books, yet the stock may still trade on other electronic communication networks (ECNs) as non-regulatory halts are not shared across exchanges. Held at the opening is in effect if a trading halt is called on a stock before the opening of the trading day. There are three main reasons why a stock is held at the opening: New information is expected to be released by a company that may have considerable impact on its stock price. There is a large imbalance in buy and sell orders in the market, or a circuit breaker has been triggered.

What is Held at the Opening?
Held at the opening is when a security is restricted from trading at the stock exchange's daily opening. Trading in the security may be halted for a variety of reasons, but is typically a temporary situation which delays the official opening of that security.



Understanding Held at the Opening
Held at the opening is in effect if a trading halt is called on a stock before the opening of the trading day. Stock exchanges can halt trading on securities at any time, but trading usually resumes in under an hour. Such halts are employed to protect investors.
There are three main reasons why a stock is held at the opening:
Trading delays are trading halts that occur at the beginning of the trading day. Traders can find trading halt and delay information on an exchange’s website.
A trading halt in general is a temporary suspension in the trading of a particular security on one or more exchanges, usually in anticipation of a news announcement or to correct an order imbalance or because a circuit breaks has been triggered (discussed below). A trading halt may also be imposed for regulatory reasons.
Trading halts
The Securities and Exchange Commission (SEC) highlights two types of trading halts and delays that may impact investors: regulatory and nonregulatory.
While the SEC cannot halt trading, it may suspend trading for up to 10 days and, if needed, revoke the security’s registration.
Regulatory halts occur when a company has pending news that may affect the security’s price. By halting or delaying trading, everyone has time to assess the impact of the news. These halts may also occur in cases when a security may not continue to meet an exchange’s listing standards.
Non-regulatory halts occur when there is a significant imbalance in pending buy and sell orders in a security. Designated Market Makers (DMM) will operate manually and electronically to facilitate price discovery during market openings..." according to the NYSE.
Sometimes the official open of exchange trading on a security will be delayed as the DMM balances the orders on their books, yet the stock may still trade on other electronic communication networks (ECNs) as non-regulatory halts are not shared across exchanges.
Exchange circuit breakers
Stock exchanges can take measures to ease panic selling by invoking circuit breakers and halting trading. As of 2020, if the S&P declines more than 7% by 3:25 p.m. EST, the market pauses for 15 minutes. If the drop exceeds 20% trading is suspended for the remainder of the session.
Example of a Trading Halt in the Real World
On March 16, 2020, as COVID-19 pandemic fears swelled, the S&P 500 continued to drop more than 7% from the prior close just after 9:30 AM EST. This halted trading in US stocks for 15 minutes as a result of a circuit breaker. Orders are not executed during this period, although orders can be placed and canceled. Trading resumed shortly at 9:46 AM.
Related terms:
Circuit Breaker
Circuit breakers temporarily halt trading on an exchange when a security or broad index moves in excess of a pre-set threshold amount. read more
Designated Market Maker (DMM)
A designated market maker is obligated to maintain fair and orderly markets for the listed firms assigned to them. read more
Electronic Communication Network (ECN)
ECN is an electronic system that matches buy and sell orders in the markets eliminating the need for a third party to facilitate those trades. read more
Flash Crash
A flash crash is an event in electronic markets wherein the withdrawal of stock orders rapidly amplifies price declines. read more
Listing Requirements
Listing requirements are the minimum standards that must be met by a company before it can list its shares on a stock exchange. read more
Lock Limit
A lock limit is a specified price movement determined by trading exchanges that if breached results in a lock on the trading instrument. read more
Opening Bell
The opening bell is rung on the trading floor of the New York Stock Exchange (NYSE) to signify the start of the day's trading session. read more
Panic Selling
Panic selling is the sudden, widespread selling of a security based on fear rather than reasoned analysis causing its price to drop. read more
Securities and Exchange Commission (SEC)
The Securities and Exchange Commission (SEC) is a U.S. government agency created by Congress to regulate the securities markets and protect investors. read more
SSE Composite
The SSE Composite is a market composite made up of all the A-shares and B-shares that trade on the Shanghai Stock Exchange. read more