Lately, whenever stock markets have appeared on edge, the solution has involved central bank intervention. Today, it was the Bank of Japan's turn to add some stimulus to the global economy, with an ambitious program of asset purchases and monetary expansion in an attempt to stem the decades-long negative impact of deflation on the island nation's economy. The greatest impact from the move came in Tokyo, where the Nikkei reversed an early slump to rise more than 2%. But even as European stocks slumped, the Dow Jones Industrials (DJINDICES:^DJI) managed to take the BOJ's move and build on it, climbing more than 55 points.

IBM (NYSE:IBM), though, fell 0.6%, which made it the biggest loser in the Dow on a percentage basis. As numerous Fool contributors have noted earlier today, Oracle scored a big win in its challenge to IBM's strategy of dominating the Big Data market, when a study showed that Oracle's technology performed better than IBM's. As troubling as that is for Big Blue, it ordinarily wouldn't have a big impact on the broader stock market. But because IBM's share price is so high, it has a disproportionately heavy weighting in the price-weighted Dow. As a result, if IBM can't resolve its problems, a stock decline could make it very hard for the Dow to advance overall.

Alcoa (NYSE:AA) also fell 0.6% as investors prepare for the aluminum company to open the official earnings season on Monday. Despite persistent weakness in aluminum prices, the company is well-positioned to take advantage of rising demand for aircraft, automobiles, and other industrial applications. As Fool analyst Taylor Muckerman noted earlier today, Alcoa's active attempts to streamline and optimize its business should prepare it to benefit greatly from the next cyclical upturn, even if the company goes through more pain in the short run.

Finally, Greenbrier (NYSE:GBX) fell more than 4% after beating earnings estimates, but falling well short on overall sales. The railroad-services company said that deliveries fell 27% during the quarter, leading to a decline in revenue of nearly 8%. Perhaps, more importantly, Greenbrier shareholders seemed dissatisfied with the way the company has moved forward after rejecting a merger bid with American Railcar Industries (NASDAQ: ARII) that activist investor Carl Icahn had tried to broker. Even with expectations of better sales ahead and a cheap valuation, Greenbrier can't seem to inspire confidence among investors.