In the following video, Fool.com contributor John Reeves gives investors some insight into three stocks that took a tumble this week. He talks about how Baidu (NASDAQ:BIDU) fell around 11% this week after its earnings report showed strong growth that just wasn't strong enough, based on analysts' lofty projections for the company. He also discusses SandRidge (UNKNOWN:SD.DL), which has now sold off its Permian basin assets and is fully concentrated in the Mississippian. The company had hoped to increase its oil production in the Mississippian, but recent results have shown a higher percentage of natural gas rather than oil in the region, which disappointed investors and had shares down by about 11%. Finally, John discusses specialty steel producer Ampco-Pittsburgh (NYSE:AP), which, though it actually increased net income, saw sales and operating income fall in the fourth quarter, citing weak global demand, and saw shares down by about 7% this week.