The rumoured bigger size iPhone 6 - 4.7 or 5.5 inches - is the catalyst to augment Apple Inc (NASDAQ:AAPL) share prices by 20 per cent, according to Jack Hough of Barron's.

As predicted by several analysts, the upcoming iPhone 6 is reason worthy enough for Apple loyal customers to upgrade or persuade back those who have switched to other devices.

"That's good news for shareholders. One recent analysis suggests the new iPhone launch could add 10%-15% of earnings upside later this year. That should rekindle interest in Apple shares (ticker: AAPL), which now trade at a deep discount to the market. Look for a gain of 20% over the next year, not counting dividends," Mr Hough wrote.

Mr Hough noted that Wall Street estimates iPhones (with a massive base of 26 million users) to bring in 54 per cent of sales as compared to iPads which will only generate 19 per cent of sales; Mac computers and notebooks for only 12 per cent of the sales for the fiscal year. All in all, the estimated revenue can reach up to $181.4 billion - a 6 per cent increase.

To support his estimate of a 20 per cent stock price hike for Apple Inc (NASDAQ:AAPL), courtesy of iPhone 6, Mr Hough cited ISI analyst Brian Marshall's analysis.

According to Mr Marshall, the percentage of iPhone users who upgrade each quarter diminished by 9 per cent from 10%-11% in 2011 and 2012, but during peak quarters, the percentage increased by 12 to 14 per cent. This precedence can happen with the iPhone 6 sales - adding more than $3 per share to share price during Apple (AAPL) September and December ending.

Will there be a dividend hike?

"I think there's a good chance of a special payout," said Barbara Marcin, who manages the Gabelli Dividend Growth Fund.

On Monday, Apple Inc. (NASDAQ:AAPL) was up by 1 per cent.

The Apple Inc. (NASDAQ:AAPL) price hike on Monday is enough reason to buy the stock based on a technical pattern observed by last quarter of 2013, according to Richard Ross, global technical strategist at Auerbach Grayson.

Mr Ross pointed out that Apple stock had been trading in a "wedge" pattern since December of 2013 - Apple's 150 day moving, when put in a chart, formed a wedge with its lower highs and higher lows.

"What we're seeing is a contraction of volatility within that wedge formation. This pattern is not necessarily directional per se but it does tell us that when we get a break from that volatility contraction - an expansion from the pattern - you want to trade in the direction from the break," Mr Ross explained.

On Tuesday, the stock is still up by 1.26 per cent at $539.621; previous close was at $532.87; day's high at $541.5 and low at $535.06, according to real-time stock quotes published by NASDAQ OMX.

"NASDAQ down 1.5% [Monday and] Apple is one of the few stocks actually higher. That's very nice relative strength, which is also a bullish tailwind. You want to be a buyer here on the break from that wedge pattern. I think the stock could trade $600 under the right circumstances," Mr Ross highlighted.

But for Portfolio manager Chad Morganlander of Stifel's Washington Crossing Advisors, Apple's stock price can go as much as $650.

"Our price target the next six to nine months out is $650. This next gen phone will be quite appealing in the not-to-distant future."

However, Mr Morganlander pointed out that while Apple is a best buy for short-term investors, the stock is not for long-term investment as there had been slow but remarkable shift towards low cost devices available in the market.

"The problem I have over the next 24 to 36 months is the business model when it comes to devices like the iPhone [and] the iPad. We are looking at a company that market cap is the largest market cap in the United States. Yes, the valuation is justified. The free cash flow is justified. And, that's why we have a price target of $650. We just wouldn't go to sleep and buy this company and own this for the next 10 to 15 years out. We'd be a little more pragmatic about it. This business model is not Procter & Gamble and certainly isn't McDonald's."