Then the market tanked, and Apple’s shares, having more than doubled in 2007, went into free fall. As the Dow dropped 10 percent, Apple dropped more than 20 percent, from a record high of 202.96 to just over 161.36 last Friday.

This will presumably change on Tuesday, when the company reports its quarterly earnings. If nothing else, day traders are likely to load up on the stock and it options, anticipating that Apple will easily beat its projected $1.42 earnings per share on sales of $9.2 billion — guidance that was considered uncharacteristically unconservative when it was offered three months ago. The street consensus is now $1.62 EPS on $9.47 billion. Piper Jaffray’s Gene Munster, always the optimist, is looking for $1.73 on $9.73 billion, and as of Jan. 14 was still calling for a price target of 250.

Even Munster doesn’t expect that kind of bounce when earnings are announced after Tuesday’s market close. What he and the other analysts will be tuning in for is the conference call that starts at 5 p.m. ET. (You can listen to the webcast here.) How Apple’s shares behave in the weeks ahead will depend on a handful of key numbers to be revealed in that call. Here are the ones the traders who hang out at The Mac Observer‘s Apple Finance Board will be listening for:

• Earnings per share. Beating guidance and meeting the street consensus is a given. The traders here are whispering about $1.80 per share, and even that wouldn’t equal the 73 percent year-to-year earnings growth Apple has achieved over the past four quarters. To do that, it would need $1.94 EPS.
• Forward guidance. Apple tends to be cautious when projecting future earnings, preferring to under-promise and over-deliver. But traders are abnormally sensitive these days to recession signals, and if the company’s forward guidance is too conservative, it could be read as a sign that even Apple is starting to feel the pinch.
• Gross margins. As the AFB moderator who calls himself DawnTreader puts it: “Volume is nice. But high-margin volume is better.” He’s watching how much of each sales dollar flowed to cover operating costs and to the bottom line after manufacturing costs.
• Mac sales. This is the key to the quarter, according to Piper Jaffray’s Munster. “If Apple sells 2.3 million units, it would be a significant positive,” he wrote in a report to clients issued last week. “2.3 million Macs represents 43% y/y growth compared to 28% y/y in Dec-06 and 20% in Dec-05.”
• Deferred revenue. I don’t pretend to fully understand the significance of the tricky way Apple accounts for its iPhone and Apple TV revenue. But this is what DawnTreader says about it: “One of the most important numbers IMHO is the net pick-up in cash exclusive of deferred revenue liabilities. Net income and EPS is impacted by a number of non-cash expenses including depreciation and amortization. How much net cash exclusive of deferred revenue and other liabilities flowed to the balance sheet?” (link)

Got that? Good luck.