The Zacks rating relies solely on a company's changing earnings picture. It tracks EPS estimates for the current and following years from the sell-side analysts covering the stock through a consensus measure -- the Zacks Consensus Estimate. As such, the Zacks rating upgrade for Mercury General is essentially a positive comment on its earnings outlook that could have a favorable impact on its stock price. The change in a company's future earnings potential, as reflected in earnings estimate revisions, has pr ...