Core Insights - Shares in Sainsbury reached a four-year high following the termination of talks to sell its Argos chain to JD.com, resulting in a stock increase of over 5% [1] Company Summary - Sainsbury's stock performance improved significantly after the decision to end negotiations with JD.com, indicating positive market sentiment towards the company's strategic direction [1] Industry Summary - The UK supermarket sector is experiencing fluctuations in stock prices influenced by major corporate decisions, such as potential acquisitions and divestitures [1]