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

Index futures suggest a flat start for the stock market today, with the Dow Jones Industrial Average (^DJI 0.06%) gaining an insignificant nine points at the opening bell. Surprisingly strong earnings results from Home Depot (HD 0.02%) are keeping the Dow near its all-time high, while Best Buy (BBY -0.30%) and Campbell Soup (CPB 0.92%) disappointed investors this morning.

But let's start with the good news. Home Depot logged blistering sales growth for its third quarter, as revenue climbed 7.4% to $19.5 billion. The home improvement retailer booked a profit spike, hitting $0.95 a share -- $0.06 better than analysts had expected. Comparable-store sales grew an impressive 8.2% in the U.S. as the recovering housing market goosed store traffic levels. Investors have bid Home Depot's shares up significantly this year. Still, the company is clearly benefiting from some broad spending trends that could keep sales and profit growth humming along for years. The stock is up 3.4% in premarket trading.

Meanwhile, Best Buy's outlook isn't nearly as cheery. The retailer reported stronger-than-expected quarterly earnings results, yet shares are down significantly in premarket trading. Sales ticked higher, hitting $9.4 billion in the third quarter, and profit grew to $0.12 a share. Best Buy was able to reverse its sales slide in the U.S, as comparable-store sales grew by 1.7%, versus a 4% drop last year. Still, gross margin fell in the quarter, and Best Buy warned that it would be matching the cutthroat promotional stance of its rivals this holiday season, which should lead to even more decreases in profitability ahead. The stock is down 6% in premarket trading.

Finally, Campbell Soup this morning reported surprisingly weak results for its fiscal first quarter. Sales shrank to $2.17 billion, below the $2.29 billion the Street was expecting. Profit fell even harder as adjusted earnings per share dove 21% to $0.66 a share. Campbell's soup and beverage businesses both turned in disappointing results, but earnings were also hurt by a ramp-up in marketing spending and the timing of this year's Thanksgiving holiday. The company lowered its full-year guidance to earnings growth of 3% on what management admitted were "disappointing" results. Campbell Soup stock is down 6% in premarket trading.