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 fundamental analysis and traditional valuation metrics to find stocks that they believe are being undervalued by the market at large.

Luckily, Zacks has developed its own Style Scores system in an effort to find stocks with specific traits. Value investors will be interested in the system's "Value" category. Stocks with both "A" grades in the Value category and high Zacks Ranks are among the strongest value stocks on the market right now.

One stock to keep an eye on is Amkor Technology (AMKR Quick QuoteAMKR - Free Report) . AMKR is currently holding a Zacks Rank of #2 (Buy) and a Value grade of A. The stock holds a P/E ratio of 5.43, while its industry has an average P/E of 12.09. Over the last 12 months, AMKR's Forward P/E has been as high as 8 and as low as 5.41, with a median of 6.42.

We should also highlight that AMKR has a P/B ratio of 1.26. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. This company's current P/B looks solid when compared to its industry's average P/B of 3.76. AMKR's P/B has been as high as 2.44 and as low as 1.17, with a median of 1.72, over the past year.

These are only a few of the key metrics included in Amkor Technology's strong Value grade, but they help show that the stock is likely undervalued right now. When factoring in the strength of its earnings outlook, AMKR looks like an impressive value stock at the moment.