FORTUNE — One of the numbers analysts watch closely when a company reports quarterly earnings is its total gross margin. It’s usually expressed as a ratio:
GM% = (total revenue – cost of goods) / total revenue
Gross margin can be thought of as a measure of how efficiently a company turns sales into profits.
In Apple’s (AAPL) case, gross margins (according to AAPLInvestor.net‘s records) have been rising fairly steadily, from 28.5% in Q1 2005 to a record 47.4% in Q2 2012 — an astonishingly high ratio for any company, especially a hardware manufacturer.
Which is one of the reasons the market reacted so badly when Apple reported its earnings last Thursday. Although gross margin for Q4 2012 came in above guidance — 40% vs. 38.5% — the company warned analysts that its GM% for the December quarter would be considerably lower: 36%.
The last time Apple reported a gross margin that low was 2008.
One of the analysts who expressed disappointment last week was Deutsche Bank’s Chris Whitmore. But he’s had the weekend to think about it, and in a note to clients Monday titled “We’ve seen this Apple margin story before” he offers some perspective.
Whitmore estimates that within two quarters Apple will have recovered roughly half of the drop in gross margin associated with the iPhone 5.
“We believe near-term margin concern is overblown,” he concludes, “and is creating a very attractive entry point for AAPL shares. Reiterate Buy.”
UPDATE: Asymco‘s Horace Dediu addressed the drop in iPhone margins in even more detail Monday.
You can read Dediu’s piece here. His chart, below, goes back to calendar Q4 2005: