Apple stock sheds 10% on growth worries Apple heightened concerns that its greatest years of growth are behind it, as it reported disappointing iPhone and Mac sales and warned of a second quarter slowdown. Shares in Apple fell more than 10 per cent, losing around $50bn in market value, in after-hours trading after it missed Wall Street's expectations for the fiscal first quarter revenues. The drop left its market value barely $20bn higher than Exxon Mobil, which it overtook to become the world's most valuable company in the aftermath of blockbuster results a year ago. Apple's shares, which fell to $461.31 compared to September's peak of $702, have weakened on investor concerns about growth, profitability and the longer-term popularity of the iPhone as the smartphone market matures in the US. The consumer electronics giant also faces cheaper competition in Asia. Apple sold a record 47.8m iPhones in the three months ended December, up 78 per cent on the prior year despite a week-shorter reporting period, with total revenues growing 18 per cent to $54.4bn. However, both figures came in below most analysts" expectations, disappointing investors, despite net profit of $13.1bn and earnings per share of $13.81 beating Wall Street forecasts. Tim Cook, chief executive, cautioned analysts to "question the accuracy" of market rumours that it had cut iPhone supply orders in December, one factor which had spooked investors before its results. "Apple is in one of the most prolific periods of innovation in its history," he said. We're very confident in our product pipeline. Apple said it sold 22.9m iPads in the Christmas quarter, up from 15.4m in the same period a year ago. Mr Cook said that supplies of the iPad mini had been "severely constrained" but that he expected demand to be met by the end of March. "We obviously could have sold more than this because we couldn't build enough iPad minis to come into demand balance," he said. Mac and iPhone 5 sales were also held back by supply constraints, while the iPhone 4 - a two-year-old product - consistently sold out for the entire period. Scott Kessler, analyst at S&P Capital, said the results were "disappointing" and cut back his earnings forecasts and price target. Analysts had expected revenues of around $55bn with earnings of around $13.44, having pared back their forecasts in recent weeks. Gross margins for Apple's first fiscal quarter of 2013 were 38.6 per cent, broadly in line with Wall Street's estimates but down from 44.7 per cent a year earlier. Apple predicted little improvement in profitability in the current period, in part because the iPad mini commands a lower margin than the larger iPad or iPhone. Mr Cook said that he expected revenues of $41bn-$43bn for the current quarter, which would be at best up 10 per cent from the second quarter of 2012, and below most analysts" expectations. Peter Oppenheimer, Apple's finance chief, said that changes to how the company provides guidance - which historically has been very conservative - would mean that its indicated range represented "what we are likely to achieve." Apple's net cash balance rose by almost $16bn in the period to $137.1bn. He also pointed to improvements in Apple's Maps app, the botched launch of which coincided with the high point in Apple's share price. "We are working on some incredible stuff - the pipeline is choc full," he said, noting that its iCloud data syncing service had now reached 250m users and that more than 2bn iMessages were sent every day.