While the proven Zacks Rank places an emphasis on earnings estimates and estimate revisions to find strong stocks, we also know that investors tend to develop their own individual strategies. With this in mind, we are always looking at value, growth, and momentum trends to discover great companies.

Of these, perhaps no stock market trend is more popular than value investing, which is a strategy that has proven to be successful in all sorts of market environments. Value investors use a variety of methods, including tried-and-true valuation metrics, to find these stocks.

Zacks has developed the innovative Style Scores system to highlight stocks with specific traits. For example, value investors will be interested in stocks with great grades in the "Value" category. When paired with a high Zacks Rank, "A" grades in the Value category are among the strongest value stocks on the market today.

One stock to keep an eye on is Alpha and Omega Semiconductor (AOSL Quick QuoteAOSL - Free Report) . AOSL is currently holding a Zacks Rank of #1 (Strong Buy) and a Value grade of A. The stock holds a P/E ratio of 9.29, while its industry has an average P/E of 16.78. Over the past year, AOSL's Forward P/E has been as high as 13.97 and as low as 6.33, with a median of 8.81.

Value investors also frequently use the P/S ratio. This metric is found by dividing a stock's price with the company's revenue. This is a prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. AOSL has a P/S ratio of 1.21. This compares to its industry's average P/S of 2.69.

These are just a handful of the figures considered in Alpha and Omega Semiconductor's great Value grade. Still, they help show that the stock is likely being undervalued at the moment. Add this to the strength of its earnings outlook, and we can clearly see that AOSL is an impressive value stock right now.