Complex sentence: Taking the previous fall into account, this represented the index's largest single-week rise since 2011, although the weak pound meant that when measured in US dollars, the FTSE 100 index remained 10% below pre-Brexit levels.
Split into simpler sentences: Taking the previous fall into account, this represented the index's largest single-week rise since 2011. However, the weak pound meant that when measured in US dollars, the FTSE 100 index remained 10% below pre-Brexit levels.