Banco Santander (NYSE: SAN) appears an attractive pick, as it has been recently upgraded to a Zacks Rank #2 (Buy). This rating change essentially reflects an upward trend in earnings estimates -- one of the most powerful forces impacting stock prices. A company's changing earnings picture is at the core of the Zacks rating. The system tracks the Zacks Consensus Estimate -- the consensus measure of EPS estimates from the sell-side analysts covering the stock -- for the current and following years. The power of a changing earnings picture in determining near-term stock price movements makes the Zacks rating system highly useful for individual investors, since it can be difficult to make decisions based on rating upgrades by Wall Street analysts. These are mostly driven by subjective factors that are hard to see and measure in real time. Therefore, the Zacks rating upgrade for Banco Santander basically reflects positivity about its earnings outlook that could translate into buying pressure and an increase in its stock price. Most Powerful Force Impacting Stock Prices The change in a company's future earnings potential, as reflected in earnings estimate revisions, ...