Plunging global markets trigger new intervention warnings in Asia

After some of the most dramatic declines in global financial markets since the Federal Reserve began lifting borrowing costs six months ago, authorities in Asia are stepping up efforts to prevent a downward spiral.

South Korea joined a growing list of interventions on Wednesday, with the central bank saying it will buy as much as $2.1 billion worth of sovereign debt. In Taiwan, officials have floated currency controls and signaled a readiness to ban stock short sales.

China has instructed some funds to refrain from large share sales and told banks to ensure the yuan’s daily fixing is