The weak pound helped the FTSE 100 stock index, stacked with global exporters, to rally more than 4% this week. Still, the more domestically-focused FTSE 250 has consistently underperformed its large cap peer this year. According to Goldman Sachs Group Inc. strategists, it’s trading at the largest P/E discount against the MSCI World index since the dotcom period. That’s “deserved given the weak outlook for UK growth, the level of GBP and the downside risks,” they wrote in a note.