It's been a so-so earnings season so far for US stocks. Just over 600 companies have reported earnings this season (through 10/24/13), and the average stock that has reported has gained 0.19% on the day of its report. (For companies that report before the open, we use that day's change. For companies that report after the close, we use the next day's change.)
The one-day performance breakdown by sector, however, shows some significant underlying trends. As shown in the chart below, Materials and Health Care stocks that have reported have done very well on their report days this season. The average Materials stock has gained 1.79% on its report day, while the average Health Care stock has gained 1.3%. Technology and Consumer Discretionary stocks, on the other hand, have done poorly on their report days. The average Consumer Discretionary stock has declined 0.49% on its report day, and the average Technology stock has done even worse at -1.14%.
It appears that investors were too optimistic about earnings for Tech and consumer-sector stocks heading into the third-quarter reporting period, while they underestimated the results of Health Care and Materials.