Why is Wall Street cooling on Apple? Apple began selling the iPhone 5 on Sept. 21, the same day the company's stock hit an all-time peak of $705.07 per share. [...] the stock has plunged nearly 25 percent, trimming the company's market value by more than $150 billion. The Nasdaq has shed 6 percent since Apple's stock price peaked while the S&P 500 has declined 3 percent, the same as the Dow Jones industrial average, which doesn't include Apple in its basket of 30 stocks. The iPhone's early lead in the smartphone market already has been surrendered to the more than 500 million devices running on the free Android software made by Google. Nokia phones running on the recently released Windows 8 system from Microsoft pose a new threat, especially in China, where Nokia has struck a deal with that country's largest wireless carrier. [...] struggling Research In Motion Ltd. is pinning its comeback hopes on a revamped operating system for the once-iconic BlackBerry to rekindle demand for that device. [...] there are signs the competition is putting pressure on Apple in the booming tablet computer industry that it launched in 2010 with the release of the iPad. In a report that probably contributed to Wednesday's steep drop in Apple's stock, research firm IDC predicted that the iPad's share of the worldwide tablet market this year will decline to 54 percent from 56 percent in 2011. Apple is running out of fresh ideas. Since Apple co-founder Steve Jobs died 14 months ago after a long battle with cancer, the company has mostly been fine-tuning products that were created under his visionary leadership. The former CEO's hand-picked successor, Tim Cook, is well-respected, but some investors are starting to wonder if Apple can conjure up another revolutionary product to catapult the company on another multiyear stretch of breakneck sales growth.