Business Week has published a hard-nosed look at Apple's share values, arguing that optimism around the firm is skewing these.

Apple, argues author Robert Barker, is "high-priced", at "37 times this year's estimated profit". The number-crunching continues, "what does $77 a share get an Apple buyer?" it asks.

He argues that despite Apple's successful year, its shares are reaching the ceiling for fair risk at present. He does so as iPod shuffles and Mac minis are selling out across the planet - but his report isn't to deny those achievements.

However, the report doesn't explain some fundamental points required to comprehend its logic. Apple's current market capitalization, for example, stands at $31.48 billion at its current share price of $77.81.

With assets valued at $22.34 per share Apple carries no debts, bar around $8.52 per share in liabilities, Business Week continues. The assets also include $15.39 per share in cash and short-term investments. (Apple actually added close to £1 billion to its cash hoard in its last quarter). Crunching down the assets leads Business Week to surmise Apple's per share asset value at around $20 - that's without taking the company's business into account.

Accepting that Apple's business is booming, the report describes four straight quarters of sales growth and net income increases. It then offers an estimate that Apple will earn $2.45 per share in the current financial year, but charges: "That still leaves Apple trading at 31 times earnings versus 26 times for Dell".

The argument is that with share values at such a high, investors face a major risk should disaster befall the firm.

In the recent past, investors could rely on Apple's assets as a cushion for stock value (around $15.39 per share, according to the report). This means disaster could see investors lose up to 80 per cent of their investment, should it strike, Business Week implies.

Apple shares dipped slightly, dropping $1.82 to close at $77.81 on yesterday's trading. Trading volumes were below average on the day.