Jakarta. Indonesia’s benchmark stock index slumped nearly 4 percent this week, marking its steepest decline in years, as investors digested fresh trade tensions. The selloff erased billions in market value and pushed foreign investors to further retreat from Southeast Asia’s largest economy.

The Jakarta Composite Index (JCI) fell 3.82 percent over the four trading sessions from April 8 to 11, closing at 6,262.23 on Friday, down from 6,510.62 the previous week. The market capitalization of the Indonesia Stock Exchange (IDX) shrank by 3.88 percent to Rp10,695 trillion ($636 billion), wiping out Rp 431 trillion in value.

Foreign investors continued their exit from the market, booking a net sell of Rp35.86 trillion ($2.3 billion) year-to-date, amid growing concerns over Indonesia’s trade prospects and global economic headwinds.

The week began with the IDX unveiling new measures to stabilize markets during periods of high volatility. In a press conference on Tuesday, the exchange announced changes to its circuit breaker policies, raising the limit for lower auto reject (ARB) to 15 percent across all stocks.

Additionally, the IDX revised its trading halt mechanism by increasing the trigger threshold for the first circuit breaker to an 8 percent drop in the JCI, up from the previous 5 percent. A second halt will occur if the index drops more than 15 percent, and a full session suspension may be imposed if losses exceed 20 percent, pending approval from the Financial Services Authority (OJK).

The move to raise the thresholds came just hours before a dramatic sell-off on Tuesday, when the JCI plunged 9.19 percent in early trading. The losses were triggered by reports that the United States had imposed new tariffs on Indonesian goods.

Markets across the globe remained volatile. On Friday, US stocks rebounded sharply, with the S&P 500 climbing 1.8 percent after a rollercoaster session. The Dow Jones Industrial Average swung from a 340-point loss to finish up 619 points, while the Nasdaq gained 2.1 percent. The rally followed China’s announcement of a 125% tariff increase on US goods, signaling deepening friction despite a temporary pause in Washington’s tariffs on some trading partners.

European and Asian markets were mixed. Germany’s DAX dropped 0.9 percent, while London’s FTSE 100 rose 0.6 percent on stronger-than-expected economic data. In Asia, Japan’s Nikkei 225 slid 3 percent, whereas Hong Kong’s Hang Seng climbed 1.1 percent.