All eyes on Apple's earnings - Update

Apple (AAPL), one of the most closely watched stocks on the Nasdaq -- and one of the engines driving the market's midsummer rally -- reports its fiscal third quarter earnings today.

None of the three dozen analysts who follow the stock think it will have any trouble beating its guidance numbers. The question is by how much.

The consensus, as reported by Thomson Financial, has been inching up and stands this morning at $1.17 earnings per share on revenue of $8.2 billion. As usual, the unaffiliated analysts -- a ragtag group of bloggers, day traders and amateur analysts who track the stock as closely, if not more so, than the professionals -- are considerably more bullish, predicting earnings in the $1.27 - $1.35 range. (See the chart below the fold.)

There is actually surprising agreement among both groups on the number of iPhones, iPods and Macs Apple sold this quarter. So why do their earnings numbers diverge so sharply?

Gross margins. Many of the pros seem to be following Apple's guidance (33%). The amateurs believe the company's margins will prove to be considerably higher -- in the 35% - 37% range -- thanks largely to the mark-up on the iPhone and the complicated way Apple books that revenue. (See How to predict Apple's gross margins.)

"If you look at the past three years of earnings," says Bullish Cross' Andy Zaky, "there has never been an instance where Q2 gross margin percentage surpassed Q3 gross margin percentage."

MacBooks flying off the shelves

Apple's gross margins in Q2 were an enviable 36.4%. Zaky is putting his bet for Q3 on 36.9%, which would translate to an EPS of $1.34.

Below: The published estimates of 17 professional analysts -- updated to include several reports issued Tuesday -- and three closely-watched amateurs. To find out who was closest to the mark, tune in here after the markets close.