In a Wednesday, March 7, 2012 file photo, Apple CEO Tim Cook announces a new iPad during an Apple announcement in San Francisco. (AP Photo/Paul Sakuma)

When Apple announces its quarterly earnings next Tuesday, it promises to be the biggest piece of market news since the last release of Apple quarterly earnings. Back in January, Apple’s earnings report was a blowout that led to unprecedented share-price growth for what was already the most valuable company in America.

Blowing past the analysts’ estimates started Apple on growth that has hit almost 67 percent since the passing of Steve Jobs last October. Apple has crossed several milestones, including passing the $600 level in share price on March 15. The stock peaked briefly at $644 on April 10, at which point the entire company was worth $600 billion. At that point, Apple had the second-largest market cap of all time, surpassed only by Microsoft, which hit $619 billion on the doubly symbolic day of December 30, 1999. That was the day before we hit Y2K, a much-feared event that drove up the stock prices of lots of software companies, and it was also the very end of the roaring Nineties.

For Apple to match Microsoft’s record, its share price would need to touch $664. For a while earlier this month that seemed like a pipe dream, as Apple’s stock ran into some rough territory after reaching the magic $600 mark. For five straight days last week, Apple dropped amid reports that demand for the iPad may be dropping, and costs for using the iPhone may be rising. On the fifth day, this past Monday, Apple fell 4.2 percent, losing $23 billion in market value in a single day. That was the stock’s biggest single daily drop since last October 19, two weeks after Jobs’ death.

Monday’s drop occurred on the day before our federal income tax returns were due, which may have had something to do with the situation. As Jason Schwarz wrote for the web site TheStreet.com, Apple’s stock underwent a similar effect just prior to last year’s tax day. In 2011, Apple’s stock was sitting at $351 on the first of April (sounds cheap now, doesn’t it?), then slid down to $320 by the 18th of the month, which was the first trading day after taxes were due last year.

That’s a drop of 9.6 percent. This year, Apple dropped 12 percent between April 10 and April 17. It’s possible that, as Schwarz suggests, some people are selling off their most valuable stock to pay their income-tax bill.

One piece of evidence in favor of that theory is that Apple immediately turned back up as soon as the stench of tax day had dissipated. On Tuesday, Apple had what was, by some accounts, the biggest day in its stock’s history. The share price jumped more than 5 percent, rising $29.57 for the biggest one-day point rise it has ever had. (There was a similar effect last year, when it jumped from $320 to $342 on April 20.)

That roller coaster ride looks likely to continue right into next week’s earnings report. It should come as no surprise that analysts have presented widely divergent target prices for Apple. Most analysts have Apple in the $700 to $750 range, but at least one — Brian White of Topeka Capital Markets — has set a price target of $1,001 for Apple stock. At that price point, its market cap would be closing in on a trillion dollars.

That’s the landscape as we head into the earnings report to be released after trading hours next Tuesday. The consensus estimates are that earnings per share will reach $9.89, with $36.27 billion in revenue. Apple’s own guidance numbers are a bit below that, with $8.50 for earnings per share and $32.50 billion in revenue. Either revenue figure would be down a bit from the $46 billion Apple reported last quarter.

So in all likelihood, Apple’s numbers will be down a bit from the last report. But Apple’s been underestimated before. In January, the average analysts’ estimate was that Apple would show a profit of $9.98 per share. Even though that was up 55.2 percent from the same quarter a year earlier, it proved woefully short: the announced profit was actually $13.87 per share.

The previous earnings report was one of the most momentous in American corporate history, so it shouldn’t be too disappointing if next week’s falls short of that. The biggest question is: How will the numbers be interpreted? Would $40 billion in revenue be considered a staggering amount, or a down quarter? Tune in to the market next Wednesday morning to see where the roller coaster is headed.

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