April 21 (Reuters) - On April 21, Shandong Xinfeng lowered its prices for liquid caustic soda. The price for 32% ion-exchange membrane caustic soda dropped to 640 yuan per ton, while the price for 50% ion-exchange membrane caustic soda fell to 1,140 yuan per ton. The plant has an annual capacity of 1.13 million tons. Chempricehub's analysis of caustic soda indicates a bearish sentiment with a score of -1.5. The price reduction for Shandong Xinfeng's liquid caustic soda, with 32% ion-exchange membrane caustic soda down to 640 yuan per ton and 50% ion-exchange membrane caustic soda down to 1,140 yuan per ton, along with the plant's annual capacity of 1.13 million tons, suggests increased supply-side pressure or weak demand, posing a significant bearish factor for spot prices of caustic soda. Combined with data from the caustic soda futures market, recent main contracts such as 2607 closed at 2,063 yuan per ton, down 11 yuan from the previous day, with open interest rising to 186,275 lots, indicating strong market pessimism. This spot price reduction may further drag down futures prices, and it is expected that the caustic soda market will remain weak in the short term, with investors advised to be cautious of downside risks.