The Taiwan Stock Exchange is reported to have summoned brokerage chairmen and chief executives over recent sharp swings in turnover.

With volume rising and falling steeply within short periods, concerns have been raised about execution delays and system load.

The exchange set out three areas: the processing capacity of order-handling systems, management of margin balances, and surveillance of algorithmic orders.

In a market where short-term trading by retail investors accounts for a high share, a system failure can translate directly into investor losses.

Volatility also continued in the night futures session, where the index opened higher before turning negative. Rising international oil prices and overseas markets are cited as background.

The exchange says it will consider further measures if needed. Brokerages will review system capacity and staffing.