President Donald Trump’s unexpected plans for a 10 per cent tariff on a further $300bn of Chinese imports is a one-two punch for Apple. China makes Apple’s iPhones and buys them. Tariffs threaten fragile improvement in both areas.

Apple shares have fallen 4 per cent since the announcement was tweeted. But concerns about the future of the iPhone were already apparent in the share price. The company trades at a relatively low forward earnings multiple for a tech company. On an enterprise value basis — excluding the $211bn in cash it holds — Apple is valued at 12 times expected earnings before interest taxes depreciation and amortisation.

This may be why Apple prefers to talk about its plans for Hollywood deals and gaming. Yet the company’s performance still depends more on iPhones than anything else. Around the world there are more than 900m iPhones in use. Sales account for almost half of Apple’s total revenue.