Investors are warming up to Apple Inc. (NASDAQ:AAPL) again, lifting shares to a 52-week high on growing enthusiasm for a new iPhone launch as well as a stock split set to take effect on June 2.

Apple shares hit a high on Monday of $607.33 but eased back on Tuesday. The stock's record high came Sept. 21, 2012 when it hit $700.01.

This week's move above $600 and the new 52-week high prompted to speculate that, "This is one of those instances where a breakout looks underway."

Several leaked details of the upcoming iPhone 6 have sparked investor interest and upbeat sales forecasts. 

In addition to the 4.7-inch iPhone 6, Apple is also rumored to be close to launching a bigger 5.5-inch iPhone, dubbed by many as the “iPhablet.” But it is unclear who could be the supplier for the larger display panels. The device is expected to be released later this fall, or in early 2014.

According to rumors, the 4.7-inch iPhone 6 could come with a resolution of 1,136 x 640 pixels, while the 5.5-inch model could sport a resolution of 1,740 x  960 pixels.

Apple Inc. will restrict vacation days for its retail store employees in September, suggesting that the company could launch the iPhone 6, its next-generation flagship smartphone, in that month, according to a new report.

Investors also seemed to welcome news of the company's recent acquisition of headphone maker Beats. The reported $3.2 billion deal would be the largest Apple has ever made.

The Cupertino, California, company's recent decision to split its shares 7-for-1 may also be perking up demand from retail investors. 

Although a stock split does not change the overall valuation of a company, the psychological effect should not be discounted.

According to a report on last month, the split is important because, “The psychological impact of the split cannot be ignored as it contributes more to the stock price than the mathematics behind the split." The author added that the split "will enhance the clientele of the stock and retail investors will have greater access."