Morningstar for 2006. Eveillard is known for his Bloomberg appearances where he insists that securities investors never use margin or leverage. The point made is that margin should be considered the anathema of value investing, since a negative price move could prematurely force a sale. In contrast, a value investor must be able and willing to be patient for the rest of the market to recognize and correct whatever pricing issue created the momentary value. Eveillard correctly labels the use of margin or leverage as speculation, the opposite of value investing. Other notable value investors include: Mason Hawkins, Thomas Forester, Whitney Tilson, Mohnish Pabrai, Li Lu, Guy Spier and Tom Gayner who manages the investment portfolio of Markel Insurance. San Francisco investing firm Dodge & Cox, founded in 1931 and with one of the oldest US mutual funds still in existence as of 2019, emphasizes value investing. Criticism Value stocks do not always beat growth stocks, as demonstrated in the late 1990s. Moreover, when value stocks perform well, it may not mean that the market is inefficient, though it may imply that value stocks are simply riskier and thus require greater returns. Furthermore, Foye and Mramor (2016) find that country-specific factors have a strong influence on measures of value (such as the book-to-market ratio) this leads them to conclude that the reasons why value stocks outperform are country-specific. An issue with buying shares in a bear market is that despite appearing undervalued at one time, prices can still drop along with the market. Conversely, an issue with not buying shares in a bull market is that despite appearing overvalued at one time, prices can still rise along with the market. Also, one of the biggest criticisms of price centric value investing is that an emphasis on low prices (and recently depressed prices) regularly misleads retail investors; because fundamentally low (and recently depressed) prices often represent a fundamentally sound difference (or change) in a company's relative financial health. To that end, Warren Buffett has regularly emphasized that "it's far better to buy a wonderful company at a fair price, than to buy a fair company at a wonderful price." In 2000, Stanford accounting professor Joseph Piotroski developed the F-score, which discriminates higher potential members within a class of value candidates. The F-score aims to discover additional value from signals in a firm's series of annual financial statements, after initial screening of