Michael Murray: Investors should dig deep for data on marketing and sales to find the real story behind a brand

The impact of an earnings disappointment on a company's share price is usually quite different to the impact of an earnings surprise. Market intelligence will usually ensure that analysts and fund managers have baked the disappointment into the price. A surprise, however, has not, by definition, been baked in - and often gives rise to distrust. In stock markets, trust trades at a premium, distrust at a substantial discount.

Last week, Royal Dutch ...