Two days after Congress struck a deal to avoid a debt default, investors bid up stocks on surprisingly good earnings. Despite a few good reports Friday, the third-quarter reporting season has just started and most companies aren’t expected to post blowout results. Earnings for S&P 500 companies are expected to have grown 3.4 percent from a year ago, the smallest quarterly increase in a year, S&P Capital IQ says. At the start of 2013, third-quarter results were expected to grow at nearly triple that pace. Investors will have a better idea of the profit picture this week as several big companies post results, including McDonalds, Boeing, Caterpillar, and Ford.