The busiest week of second-quarter earnings season is underway.
Wall Street is preparing for a flood of corporate results over the next several days.
S&P 500 earnings growth has been heavily skewed by the performance of a single company.
That company has generated a disproportionate share of overall profit gains in the index.
Excluding this firm, aggregate earnings growth for the S&P 500 would look significantly weaker.
Investors are now watching to see if other sectors can catch up.
The concentration of earnings power raises concerns about market breadth.
Broad market performance depends on whether more companies deliver strong results.
Analysts warn that reliance on one stock creates risk for the broader index.
If that company falters, overall earnings growth could quickly turn negative.
