Taiwan shares closed below the 40,000 mark on July 30 after a volatile session in which the benchmark index swung more than 1,700 points. An intraday rally of more than 1,100 points was erased by late selling Focus Taiwan reported.

The Taiex ended down 105.88 points, or 0.26%, at 39,933.30. Turnover totalled TWD1.10 trillion, equivalent to about $34bn.

The sharp swings followed a two-day sell-off earlier this week that wiped 3,595.01 points from the index.

The Taiex fell more than 600 points early in the session to 39,404, close to its 120-day moving average of about 39,327. It then rebounded to an intraday high of 41,155, up 1,116 points from the day prior, before renewed selling pushed the index back into negative territory.

The Taiex has now fallen more than 6,192 points in July, and is on course for its largest monthly points decline on record.