https://www.theguardian.com/technology/2019/jan/03/iphone-slump-the-rivals-taking-a-bite-out-of-apple

As firm’s stock falls over sales warnings, it has competition in bid to be best smartphone

As Apple’s shares tumble following its cut in forecasts, the company is laying the blame squarely on the economic slowdown in China. But that’s only part of the problem.