Apple’s stock plumbed new depths last Monday just as Google hit an all-time high, reflecting Wall Street’s struggle to come to terms with the rapid shifts in the smartphone market, according to a Financial Times report.

The investor rethink about the prospects of the two tech companies has led to a striking readjustment in valuation, with Google climbing from barely a third of Apple’s worth six months ago to more than two-thirds yesterday, or $267bn.

At Monday’s close, Apple’s market capitalisation stood below $400bn for the first time in more than a year.

Reports say that Apple could introduce a new smart watch as soon as this year and an endorsement of chief executive, Tim Cook’s strategy from Warren Buffett failed to counter the negative sentiment that has plagued Apple’s shares, which are now 40 per cent below their highs.

Some Apple investors, led by Greenlight Capital’s David Einhorn, have been pushing the company to pay out more of its $137bn cash pile, something founder Steve Jobs long resisted.

On Friday, Mr Einhorn dropped a lawsuit against Apple over corporate governance changes but continues to push for higher returns of cash, something Mr Cook has said the board is actively considering.

Speaking on CNBC on Monday, Mr Buffett said that if he were in Mr Cook’s shoes, he “would ignore” Mr Einhorn but added that he did advise the late Mr Jobs to buy back stock.

“I would run the business in such a manner as to create the most value over the next five to 10 years. You can’t run a business to push the stock price up on a daily basis,” the Berkshire Hathaway chief said. “I think Apple’s done a good job of building value. They may have too much cash.”

Apple’s recent stock market weakness stands in stark contrast to the strong momentum in Google’s shares, which have risen by 15 per cent since the start of 2013. At the same time as investors’ love affair with the iPhone has waned, many have warmed to Google’s prospects in mobile.

Its Android smartphone operating system has gained market share at the iPhone’s expense over the past two years, and Samsung is set to unveil its latest flagship Android device, the Galaxy S4, this month.

Wall Street’s worst fears that the shift to mobile would devalue Google’s advertising have been dispelled in recent weeks. In January, Google reported that it had managed to hold the decline in its overall pricing to 6 per cent in the final months of last year.

That news, along with other indications of strong momentum in its core search business, sparked a rally that has since seen its shares rise by nearly 16 per cent, pushing them through $800 for the first time two weeks ago.

At the close in New York, Google had climbed 1.9 per cent to $821.12, a new high, while Apple’s stock was down 2.5 per cent to $419.57.

Last week, Mr Cook said he sympathised with “disappointment” among Apple shareholders about its stock price, saying: “I don’t like it either . . . We are focused on the long term.”