The KRX operates various systems for keeping
an orderly market, as listed below, since
the Korean
markets, unlike their U.S. counterparts,
do not have intermediaries or specialists
responsible
for market-making.
Daily
Price Fluctuation Limits
To
protect investors from excessive fluctuations
of stock prices, the KRX sets a daily price
fluctuation limit at 15 percent of the previous
day's closing price
Suspension
of Trading
When a particular issue's share price and/or
trading activities show an abrupt movement
before the opening of or during trading, the
KRX may halt the trading of such an issue
for investor protection.
In such cases, the company will be ordered
by the KRX to disclose any information relevant
to the abnormality. If the disclosure proves
satisfactory, the issue may resume trading
in the next session.
Administrative
and Surveillance Issues
When an issue falls under the delisting criteria,
the KRX may designate it as an administrative
issue to warn investors of possible exposure
to excessive risk.
Administrative issues are traded under a special
transaction method whereby all orders of such
stocks received during a trading session are
regarded as simultaneous orders. These are
subject to auction at a single price.
Surveillance issues are those designated by
KRX as showing unusual price movements.
Administration and surveillance issues are
neither eligible for margin trading nor permitted
for use as substitute securities.
Market
Surveillance Activities
To ensure a fairly operating stock market,
the KRX introduced its second-generation market surveillance
system, the Consolidaded Securities Market Monitering and Surveillance
System(COSMOS).
กค
The computerized system is used to detect
price manipulation, insider trading, and other
questionable practices involving stock
trading.
กค Morever, it is used to address increasing new trading techniques and trading volume.
Market surveillance takes place in two steps under COSMOS,
using two sub-systems : the Market Monitering and Alert Sytem(MAS) and Market Surveillance
and Information System(SIS).
Management
of the Market 
When a particular issue's share price and/or
trading activities show an abrupt movement
before the opening of or during trading, the
KRX may halt the trading of such an issue
for investor protection. 
