What it is
Program trading bundles many stocks into a single order that institutions or foreign investors execute automatically based on preset conditions.
Types
Arbitrage trading exploits price gaps between futures and cash; non-arbitrage trading buys or sells index baskets regardless of that gap.
What to keep in mind
Heavy program buying lifts large caps and the index, and futures and options expiry days can bring big closing swings as arbitrage positions unwind.
Where to check
The Korea Exchange publishes program trading totals during and after the session. Arbitrage unwinding clusters on expiry days — index options expire the second Thursday of each month, index futures only in March, June, September and December — which are listed on the market calendar page.
This explanation is general information, not investment advice. Rules reflect September 2026 and may change; check official exchange and broker notices.