Public trust in the financial sector has taken a beating, for all-too-obvious reasons. But a new TNS report finds Americans have been discriminating in their withdrawal of confidence. Respondents were asked whether they could trust various sorts of financial institutions, and some types fared far worse than others. All of 9 percent said they could trust brokerage/investment companies, and the same number said they could trust insurers. The category “large national banks” fared just slightly better (20 percent). But many more said they could trust smaller regional banks (41 percent) or credit unions (45 percent). Gathered in October/November, the data give reason to suspect small banks could grab market share from big banks if they were so inclined in these risky times.