Chatfeild-Roberts: How Apple could make or break your portfolio

Investors are concerned recent sharp moves in Apple's share price are distorting returns for the wider US market, suggesting some indices may have to be rebalanced to lessen the tech giant's dominance.

Apple saw its share price hit a record $644 on 10 April, and although shares have subsequently dropped back some 11%, the stock remains up 42% year-to-date ahead of today's Q2 earnings figures. This price volatility has increased concerns the world's largest company by market capitalisation, at $550bn, carries excessive risks for the performance of the entire S&P 500 index. Some US analysts have warned even a small squeeze on margins could have a significant knock-on impact on wider US equity performance. Jupiter's chief investment officer John Chatfeild-Roberts said although the U...