What is that warm, tingly feeling that Vittorio Colao feels when he wakes? What makes the challenges facing Vodafone’s chief executive weigh so lightly? Traders know it. It is the enduring satisfaction that comes from selling big, right at the top.

The feeling must be particularly vivid this week. Verizon (in the fifth paragraph of an otherwise deliriously upbeat news release) said that contract customers were departing at higher rates “in this highly-competitive and promotion-filled fourth quarter”. Wireless margins will be under pressure too. Big peer AT&T made similar remarks. The smaller competitors in the US, Sprint and T-Mobile, are desperate and dangerous.

Mr Colao agreed to sell Vodafone’s 50 per cent stake in Verizon’s wireless business in September of 2013 for $130bn in cash and shares. So he can look at the foul weather in the US from a distance. Subscriber growth has held steady at the big players, but revenue per subscriber trends have been shaky since Vodafone and Verizon shook hands. Shares in all four competitors have underperformed the market badly since then.