What it is:
Delisting refers to the removal of a security from active trading. It generally occurs when a company goes private, is bought out, declares bankruptcy or fails to meet listing requirements.
How it works/Example:
Voluntary delisting might occur if a company is acquired or goes private. Involuntary delisting occurs when a company fails to meet the listing requirements as determined by the exchanges it trades. Listing requirements can be very complex and different types of issuers and securities may have different rules, but generally the guidelines include filing financial statements in a timely manner, a share price above a certain price, a minimum number of shareholders, a minimum market capitalization , or certain revenue, profit, cash flow and trading activity requirements.
To understand how the delisting process generally works, let's consider the stock of Company XYZ. The NASDAQ delists companies that have closing bid prices below $1.00 for 30 consecutive days or more. So if Company XYZ stock closes below $1.00 on the 31st day, the NASDAQ sends a noncompliance letter to Company XYZ informing it that its stock has to start closing above $1.00 in the next 180 days (issuers that fall out of compliance with an exchange's listing requirements are usually not delisted immediately; they are given time to resolve the situation). The exchange will then add Company XYZ to its list of noncompliant issuers.
If, after 180 days, Company XYZ stock is still trading below $1.00, NASDAQ will delist the issue. Usually an issuer has the right to appeal a delisting. This acts as a stay against the delisting in many cases. But if the issuer loses the appeal, the security is delisted. The exchange suspends trading in that security and notifies the issuer and the Securities and Exchange Commission (SEC) in writing and releases a press release.
Why it matters:
Although not all companies are delisted for negative reasons, delisting prevents exchanges from being filled with shoddy securities from issuers that may be on their last leg. By ensuring that all issuers maintain high administrative standards, exchanges are helping to reduce the systematic risk associated with the market and protect investors.