Maybe there is more to Apple’s decision that, starting with its next quarterly report, it will no longer give sales-unit figures for the iPhone?

On Monday, Apple shares fell as much as 4 percent to $196.71 after Lumentum, a Milpitas company that makes facial recognition technology that is used in Apple’s iPhones, said it was cutting its sales forecast for its 2019 fiscal second quarter due to what it called a “customer development.” Lumentum went on to say that “development” was that one of its “largest industrial and consumer customers” asked it to “materially reduce shipments” for laser diodes used in 3D-sensing applications.

In other words, one of Lumentum’s biggest customers said it doesn’t need as much of Lumentum’s products as it previously thought it would. Lumentum didn’t say which customer that was, but speculation immediately turned toward Apple.

Such speculation shouldn’t come as a surprise to anyone. When Lumentum filed its 2018 annual report, it said Apple was its largest customer, and accounted for 30 percent of Lumentum’s sales. When Lumentum issued its revised sales forecast, it said it expects its quarterly sales to be between $335 million and $355 million, compared to an earlier estimate for sales in a range of $405 million to $430 million.

That new sales outlook was enough to drive Lumentum’s shares down by more than 30 percent to $38.66 on Monday.

Apple didn’t immediately return a request for comment.

Apple’s shares have fallen 11.5 percent since Nov. 1, when the company gave a quarterly sales outlook that disappointed Wall Street and said that going forward, it would no longer provide sales figures for iPhones, iPads and Mac computers.