Wall Street churned to a mixed finish as a long list of worries looms, even if the most pressing crisis seems to be calming as Washington moves to avoid a default on its debt.
The S&P 500 was virtually unchanged Tuesday, hovering near its highest level since August. The Dow Jones Industrial Average fell 50 points. The Nasdaq composite led the market with a 0.3 percent gain as excitement built further about artificial intelligence.
