It's been quite a while since Apple (NASDAQ:AAPL) traded at these levels, but shares broke back through the $600 threshold this week. That was the first time in over 18 months. However, a lot has changed over that timeframe and Apple's fundamentals have only strengthened.

On a trailing-12-month basis, revenue is 13% higher while iPhone unit sales have jumped nearly 30%. Apple's pullback wasn't entirely attributed to deteriorating fundamentals though. A lot of the underperformance can be attributed to a lack of investor confidence, since Apple investors can be an emotional crowd.

On that front, Apple's massive share repurchase program has helped investors regain confidence in the Mac maker. When the capital return program was initiated in 2012, the share repurchase authorization was just $10 billion, or about 20% of the total planned capital return. Now, that figure stands at $90 billion and comprises 70% of the total planned capital return. All the while, investors await Apple's entry into new product categories, as Tim Cook continues to reiterate.

In this segment of Tech Teardown, Erin Kennedy discusses Apple at $600 with Evan Niu, CFA, our tech and telecom bureau chief.

Erin Kennedy owns shares of Apple. Evan Niu, CFA owns shares of Apple. Evan Niu, CFA has the following options: long January 2015 $460 calls on Apple and short January 2015 $480 calls on Apple. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.