January was the worst month in a very long time for Apple stock.
How bad was it?
At the close of trading Thursday, Apple shares had lost more than 14 percent of their value since New Year's Day. That kind of monthly loss has only happened to the Cupertino powerhouse three other times in a decade. The last time? September 2008.
(Read More: Why Apple Stock Fell So Far So Quickly )
But really, that doesn't fully capture the impact of the stock's tumble. That's because while Apple tumbled, the broader markets were having a banner start to the year, with the Nasdaq up 4.1 percent and the S&P 500 up 5 percent.
How unusual is that? Since the year 2000, there had never been a month when Apple lost more than 14 percent while the Nasdaq rose. There had been only one month when Apple lost more than 14 percent while the S&P rose, back in May 2001, but that was a half a percent.
(Read More: Sell-Off Costs Apple 'World's Most Valuable' Mantle )
It's an interesting exercise to look back at Apple's other big tumbles since the dot-com bust and what caused them:
June 2002: Apple warned that revenue and earnings would come short of expectations on some weakness in Mac sales to creative professionals in a weak economy. Apple tumbled 23.95 percent; the S&P lost 7.25 percent and the Nasdaq lost 9.44 percent.
May 2006: Apple CEO Steve Jobs apologized for stock option backdating in the late 1990's, amid questions about whether Apple would be in legal trouble. Apple fell 15.09 percent; the S&P lost 3.09 percent, the Nasdaq 6.19 percent.
(Read More: Apple Loses Appeals Bid in Samsung Patent Battle )
January 2008: Investors were disappointed in a post-iPhone Macworld keynote where Jobs unveiled nothing but iTunes movie rentals and the MacBook Air. (Hindsight is 20/20.) Apple fell 31.66 percent; the S&P lost 6.12 percent, the Nasdaq 9.89 percent.
September 2008: In a slow economy, two banks downgraded Apple on a litany of fears.
They feared Apple was slowing iPhone orders. They feared Apple's margins were dropping. They feared that people would stop buying Apple's high-end wares. Apple fell 32.96 percent; the S&P lost 9.08 percent, the Nasdaq 11.64 percent.
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And then we have this January, where investors fear Apple's iPhone sales growth is slowing, that its margins are narrowing, and that competitors have begun to erode its cool. Unlike so many of those other cases though, investors are really jazzed about the markets in general. Even with BlackBerry's precipitous tumble over the last week, it was positive for the month.
(Read More: All the Reasons Blackberry 10 Will Fail: Analyst )
All of that makes January a month to forget for Apple investors, and brings new meaning to TGIF: Thank Goodness It's February.