Apple's new CEO faces his first big test

Every chief executive officer gets one free sentence on the way in. It becomes the line people quote back three years later, usually with a scoreboard attached.

Most of them know this and say nothing memorable on purpose. Vagueness is cheap. Specificity is a liability you carry into every earnings call that follows.

Apple (AAPL) has been unusually good at that discipline. Under Tim Cook, who ran the company for 15 years and moved into the executive chairman role on Sept. 1, the corporate voice stayed flat by design.

Cook built a business on more than 2.5 billion active devices and quarterly revenue above $100 billion, and he almost never described a product before it existed. Restraint was the house style, and investors priced it in.

That is the setting for what happened Sept. 1, when Apple's longtime hardware chief became its eighth chief executive in a 50-year history.

John Ternus broke the house style on his first morning.

Ternus told employees that "we have a huge launch next week that's going to be phenomenal," in a memo first reported by Bloomberg and published in full by 9to5Mac .

What Apple already told Wall Street about this quarter

The memo reads like standard first-day warmth until you put it next to Apple's own numbers, which is exactly what I did before writing a word of this.

Apple posted June-quarter revenue of $109.4 billion, up 16% from a year earlier, with diluted earnings per share of $2.02 and gross margin of 50.1%, according to the company's earnings release filed with the Securities and Exchange Commission . Every one of those was a June-quarter record.

Then management gave guidance, and the stock fell more than 6% in extended trading.

Apple projected September-quarter revenue growth of 9% to 11%, short of analyst expectations for 12%, according to CNBC . Gross margin was guided to 47% to 48%.

Finance chief Kevan Parekh pointed to a 2.5 percentage point currency headwind and supply constraints that would increase from the June quarter. Cook described the component situation as "a 100-year flood" in memory pricing, according to the earnings call transcript published by Investing.com .

So Ternus inherited a company that had just told Wall Street the growth rate was coming down and the margin was coming down with it.

One word in Ternus's memo carries real risk

"Phenomenal" is not a neutral word. It is a forecast — delivered by the one person at Apple whose forecasts now move the stock — about an event nine days away.