Investors with an interest in Financial - Investment Management stocks have likely encountered both Affiliated Managers Group (AMG) and BrightSphere Investment Group (BSIG). But which of these two companies is the best option for those looking for undervalued stocks? Let's take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Affiliated Managers Group has a Zacks Rank of #2 (Buy), while BrightSphere Investment Group has a Zacks Rank of #5 (Strong Sell) right now. The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that AMG has an improving earnings outlook. However, value investors will care about much more than just this.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks that they believe are undervalued at their current share price levels.Our Value category grades stocks based on a number of key metrics, including the tried-and-true P/E ratio, the P/S ratio, earnings yield, and cash flow per share, as well as a variety of other fundamentals that value investors frequently use.AMG currently has a forward P/E ratio of 10.09, while BSIG has a forward P/E of 15.67. We also note that AMG has a PEG ratio of 0.61. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. BSIG currently has a PEG ratio of 0.65.Another notable valuation metric for AMG is its P/B ratio of 2.21. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, BSIG has a P/B of 4.34.Based on these metrics and many more, AMG holds a Value grade of A, while BSIG has a Value grade of C.AMG has seen stronger estimate revision activity and sports more attractive valuation metrics than BSIG, so it seems like value investors will conclude that AMG is the superior option right now. Bitcoin, Like the Internet Itself, Could Change Everything Blockchain and cryptocurrency has sparked one of the most exciting discussion topics of a generation. Some call it the “Internet of Money” and predict it could change the way money works forever. If true, it could do to banks what Netflix did to Blockbuster and Amazon did to Sears. Experts agree we’re still in the early stages of this technology, and as it grows, it will create several investing opportunities. Zacks’ has just revealed 3 companies that can help investors capitalize on the explosive profit potential of Bitcoin and the other cryptocurrencies with significantly less volatility than buying them directly. See 3 crypto-related stocks now >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Affiliated Managers Group, Inc. (AMG): Free Stock Analysis Report BrightSphere Investment Group Inc. (BSIG): Free Stock Analysis Report To read this article on Zacks.com click here.