The FTSE 100 index experienced a stable to slightly positive movement on Monday, as investors watched a new trade agreement between the UK and the U.S. come into play. This agreement has notably reduced tariffs on British car exports from 27.5% to 10% and has eliminated duties on aerospace goods, including engines and aircraft parts. However, a standard 10% car tariff still applies, and negotiations for zero tariffs on key steel products are ongoing. In economic indicators, the UK's GDP growth for the first quarter was confirmed at 0.7%. Among the market movers, Rolls-Royce saw an increase of over 1.5%, Fresnillo advanced by more than 1%, and BAE Systems gained nearly 1%. On the downside, Centrica's shares fell by 2%, following a downgrade by JPMorgan. Furthermore, WH Smith saw its stock decrease by 6% after reporting lower-than-anticipated returns from the sale of its high street business. Similarly, TT Electronics' shares dropped more than 7% after it disclosed reduced revenue over the first five months of the year.