Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis

U.S. stocks opened slightly higher this morning, with the S&P 500 (SNPINDEX:^GSPC) and the narrower, price-weighted Dow Jones Industrial Average (DJINDICES:^DJI) up 0.08% and 0.21%, respectively, at 10:05 a.m. EDT.

Last Friday, I explained why retail's ugly series of earnings reports was the week's most important trend, but this week appears to be offering something of a counterpoint to that observation.

On the face of it, J.C. Penney's (NYSE:JCP) results were nothing to write home about. Same-store sales at the ailing retailer fell 11.9% in the quarter, versus the 7.4% Wall Street analysts had forecast (same-store sales refer to revenue from stores open at least one year in order to establish a like-for-like basis for comparison).

Excluding items, Penney lost $1.17 per share, falling $0.11 short of Wall Street's consensus estimate. However, the company described the back-to-school season as "encouraging." Investors approve, sending the shares up 1.7%.

Meanwhile, electronics retailer Best Buy (NYSE:BBY) recorded its first profitable quarter in a year and blew past expectations in the process, with profit of $0.32 per share (ex-items) easily topping the $0.12 per-share consensus forecast. The market is certainly showing its appreciation this morning, with Best Buy shares up 10%.

The company's turnaround is clearly gaining traction, but the improvement in operating results owes largely to better cost controls, while growth remains elusive: Total revenue fell 0.4% year on year, with sales at U.S. stores open at least 14 months suffering the same percentage drop (globally, the equivalent decline was 0.6%).

In terms of quality of results, though, today's unqualified winner is Home Depot (NYSE:HD). Yes, the margin of its "beat" was smaller than Best Buy's, as the home improvement retailer earned $1.24 per share versus a consensus estimate of $1.21. Yet it was achieved on revenue growth of 9.5% and same-store sales growth of 10.7% -- significantly faster than the growth rate of the economy during that period. The company even had the chutzpah to raise its guidance for the year by $0.08 to $3.60. If that isn't evidence that the housing market -- a key contributor to the economy -- has turned a corner, then it has me fooled.

Downbeat data alternating with better data, and vice versa -- that's the story of the post-crisis recovery. Today's series of retail earnings are certainly an improvement over last week's, but they still highlight (for the most part) that growth remains a challenge. That owes partly to a secular shift in shopping habits, but muted growth is still a reality in this economic environment.