CUPERTINO, Calif. ( TheStreet) -- Apple has climbed 11% in March on positive iPad sales forecasts and increased consumer spending. Still, some investors shun Apple because they expect a drop or consider the stock overpriced.Here are five inhibitions that could be hurting your returns. 5. Aversion to groupthink: The technology bubble of the late '90s and the credit bubble of 2006 have stoked skepticism among investors. They avoid popular stocks because they've been burned by fast-growing names in the past. Apple repels many investors who question why shareholders are so emotionally attached to the company and its products. As long as you're buying shares based on investment fundamentals, not emotion, Apple is a safe bet. 4. Newton's Third Law: Isaac Newton's Third Law of Motion states that "to any action there is an equal and opposite reaction." The Third Law is rarely discussed in finance, but it affects how we purchase stocks. Prices move in two directions. When a stock rises like Apple's has, it seems like a descent looms. The popularity of the Fibonacci sequence, a series of ascent and retracement patterns in technical analysis, has exacerbated this fear of natural corrections. 3. The value proposition: The success of Warren Buffett has made value investing the preferred strategy of many investors. However, many analyze valuation metrics, such as price-to-earnings and price-to-book ratios, without comparing them to peer or market averages. When evaluating a stock, investors must consider factors such as geographic, economic and industry prospects as well as expected individual growth rates. If you're waiting to "pick your spot" on Apple, you'll have missed out on serious growth. 2. Contrarian myopia: There is a sizable group of investors who believe they have superior insight. They aren't in the market to make money, but to prove their atypical talent. Such contrarians consider themselves to be "ahead of the curve" and scorn popular investment ideas for being banal or simplistic without fully considering their merits. This group fails to recognize that a contrarian predisposition often prevents one from owning lucrative stocks. 1. Premature cognitive closure: A person on a chosen course is likely to stay on that course, regardless of new information. People are naturally inclined to cling to preexisting opinions. This will prevent them from purchasing Apple shares, except under certain circumstances. If the stock falls or the company declines in popularity, you could see a new wave of investors buying into Apple. In this way, inhibitions provide a stock-price cushion. Now, here are four fundamental reasons to buy Apple shares.