earning yield vs price change?

AAPL is a bad example because of its explosive growth rate, valuations on stocks like AAPL might be tough to figure out using traditional metrics.

Take a look at growth names like MSFT, GE, PFE etc, you will find the fundamentals are more in line with what you expect.

The confusion with AAPL is that it trades on expectations of booming earnings in the years to come, this is why you hear people say "priced for perfection". If there is a small hiccup in AAPL, say a strike at the production plant, there will be a huge % move in the stock.

Stock prices will always fluctuate so you will not get perfect numbers.

Earnings could be great, but if the broader market is selling off due to Greece/high oil prices/Iran war threats/bird flu, you get situations where the stock is undervalued because it is being sold off with everything else.

This is where fundamentals shine.

If your stock is being unfairly beaten down, pays a nice dividend and earnings are unaffected by what ever the market is worried about, you have yourself an opportunity to buy something on sale.

There are many different schools of thought when it comes to picking a "good" stock. For the most part they are all pretty good for the long term investor.

One example is the CANSLIM method:

• C stands for Current earnings. Per share, current earnings should be up to 25%. Additionally, if earnings are accelerating in recent quarters, this is a positive prognostic sign.

• A stands for Annual earnings, which should be up 25% or more in each of the last three years. Annual returns on equity should be 17% or more

• N stands for New product or service, which refers to the idea that a company should have a new basic idea that fuels the earnings growth seen in the first two parts of the mnemonic. This product is what allows the stock to emerge from a proper chart pattern of its past earnings to allow it to continue to grow and achieve a new high for pricing. A notable example of this is Apple Computer's iPod.

• S stands for Supply and demand. An index of a stock's demand can be seen by the trading volume of the stock, particularly during price increases.

• L stands for Leader or laggard? O'Neil suggests buying "the leading stock in a leading industry". This somewhat qualitative measurement can be more objectively measured by the Relative Price Strength Rating (RPSR) of the stock, an index designed to measure the price of stock over the past 12 months in comparison to the rest of the market based on the S&P 500 or the TSE 300 over a set period of time.

• I stands for Institutional sponsorship, which refers to the ownership of the stock by mutual funds, particularly in recent quarters. A quantitative measure here is the Accumulation/Distribution Rating, which is a gauge of mutual fund activity in a particular stock.

• M stands for Market indexes, particularly the Dow Jones, S&P 500, and NASDAQ. During the time of investment, O'Neil prefers investing during times of definite uptrends of these three indices, as three out of four stocks tend to follow the general market pattern.

You can also try a stock screener, enter the fundamentals you are looking at and see what matches come up:

http://finviz.com/screener.ashx?v=111&ft=2