Apple's stock sank in Friday's premarket, a day after the company reported disappointing iPhone shipment data and provided guidance for its first fiscal quarter that fell short of analyst expectations.

But Wall Street analysts told clients on Friday they were concerned about management's decision to stop breaking apart iPhone unit sales, an insight some investors used to gauge demand for the company's latest products.

Longtime tech analyst Daniel Ives of Wedbush Securities criticized Apple's decision to halt updates on unit sales and average selling price data.

"The 'jaw dropper' last night was when Apple announced it will stop providing units/ASPs for iPhones, Macs and its other product lines," Ives said in a note Friday. "The Street will find this a tough pill to swallow this morning as the transparency of the Cupertino story takes a major dent given that tracking iPhone units has become habitual to any investor that has closely followed the Apple story for the last decade or more and is critical to the thesis."

Jefferies analyst Timothy O'Shea said the decision may fuel fears that Tim Cook-led company may be trying to conceal softer sales in the future.

"Apple will stop disclosing unit sales figures next quarter, fueling fears the company has something to hide," O'Shea told clients in a note. "But Apple will disclose Services gross margin for the first time ever, a potential catalyst for the stock."

Here's what Wall Street's major analysts thought of Apple's latest results.