The FTSE 100 started Tuesday on a positive note, with gains driven by recovering metal prices and a rally in mining stocks. European markets mirrored this upward trend. A.G. Barr's stock saw a 6.1% rise after reporting positive financial results, including a 4% revenue increase to £437 million. This positive momentum reflects broader market sentiment.

AstraZeneca's stock dipped following the FDA's rejection of its subcutaneous injection form of the Saphnelo lupus drug. The company is working to address the FDA's concerns. Plus500 launched a US prediction markets platform, offering event-based contracts through its trading platform. These developments highlight the dynamic shifts in the UK market.

UK grocery inflation eased to 4.0% in the four weeks to January 25, the lowest since April last year. This easing provides some relief to consumers. Investors will be watching how these individual stock performances and economic indicators shape the FTSE 100 throughout the trading day.

Overall, the market's response to these diverse news items, including the performance of companies like A.G. Barr and AstraZeneca, reflects a cautious optimism. The trading day will reveal whether these early gains can be sustained amid fluctuating global market conditions and sector-specific news.