On September 12, during intraday trading, SK Hynix's stock price surged by 5%. This followed the company's prior announcement that it had not only completed the development of the world's first HBM4 (High - Bandwidth Memory 4) but also established a system for mass - producing it. In the English - speaking business world, when reporting on stock - related news, it's common to use more vivid verbs like "surged" instead of the relatively plain "rose" to better convey the dynamic change in the stock price. Also, the original sentence structure was a bit straightforward. By re - arranging it to put the time "On September 12, during intraday trading" at the beginning, it gives a clearer time frame for the event right from the start. And splitting the long announcement content into a more detailed description after "not only...but also..." makes the sentence more logical and easier to understand, which is in line with English expression habits.