Apple (NASDAQ:AAPL) shares have taken a beating lately, sinking 38% since the start of October. Here's a look at the four darkest moments of this sustained bear attack.

Apple Downs

AAPL data by YCharts

Let's start at the beginning, with the entry marked "1" in the preceding chart.

Apple presented the iPad Mini on Oct. 23, as expected. But the company also introduced an updated iPad at the same time. The last iPad refresh was less than six months old at the time, and the accelerated product cycle raised eyebrows -- and sent shares plunging 3.3% in a single day. As for the Mini, I was left wondering why the tablet was priced at such an awkward level. At $329 a pop, the iPad Mini cost 65% more than an (NASDAQ:AMZN) Kindle Fire of the same size, and it was just an 18% discount to the much larger full-sized iPad.

In early December, market research firm IDC reported that Apple was losing market share in the tablet arena. Worries about the then-upcoming fiscal cliff already weighed on the world's largest stock (in terms of market cap), and the sinking tablet share released it all as a 6.4% one-day price drop.

Apple's first-quarter rolled around in January, and it confirmed the bearish arguments. iPhone sales turned out to be slower than analysts had expected, and there was a downright unhealthy shift from latest-and-greatest to older-and-cheaper handsets in this holiday quarter. Apple's margins are under pressure, and its formerly unstoppable sales growth is slowing down. The iPad Mini undermined Apple's average selling prices but didn't appear to boost unit sales much. Shares fell a hair-raising 12.4% that day.

That brings us to the fourth and final stop on this whirlwind tour. The week before Apple's next earnings report, audio-chip supplier Cirrus Logic (NASDAQ:CRUS) scared the pants off many Cupertino investors with an earnings miss and very low top-line sales. Apple is Cirrus' largest customer by far, and it was easy to connect the dots. Management blamed the miss on "a decreased forecast for a high volume product," and Apple shares plunged another 5.5% overnight. When Apple's report confirmed the bearish action again, the bad news had already been priced in. That's why the stock didn't sink even further this week.

Apple's high-margin business model is falling apart at the seams, and I suddenly don't feel particularly contrarian for having a thumbs-down CAPScall on Apple's stock.

Fool contributor Anders Bylund holds no position in any company mentioned. Check out Anders' bio and holdings or follow him on Twitter and Google+.

The Motley Fool recommends and Apple and owns shares of, Apple, and Cirrus Logic. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.