Global investment banks had a remarkable start to the year. But the rally has gone far enough. Shares in Goldman Sachs Group, Morgan Stanley and J.P. Morgan Chase have doubled from their lows, while European wholesale banks also are up sharply. Shares in Barclays, for instance, have tripled since early March. Yet big questions remain over their future business models, making further price rises hard to justify. Sure, the banks were due a rally after they used their 2008 results to finally mark toxic exposures to realistic prices. That relief turned to excitement as it became clear the industry was ... http://online.wsj.com/article/SB123906523486595437.html Need a subsription to read...