Dollar General (DG -0.97%) stock traded sideways after the company reported third-quarter earnings on Thursday, but it's taking a nice leg upward Friday morning. The dollar store chain earned $0.89 per share in Q3, a nickel short of the $0.94 Wall Street forecast for it, but edged out sales forecasts with $10.2 billion in Q3 revenue.

As of 10:20 a.m. ET, Dollar General stock is up 5%.

Dollar General Q3 earnings

Dollar General reported 5% sales growth year over year, with new store openings providing most of the growth. Same-store sales grew barely 1%. Worse, earnings plunged at the retailer, with operating profit falling 25% and earnings per share down 29%.

Despite the lousy news, CEO Todd Vasos pronounced himself "pleased with our team's execution in the third quarter," noting that while same-store sales were weak, they were still "near the top end of our expectations for the quarter."

Investors weren't impressed, though, and Dollar General stock hardly moved at all yesterday. It probably didn't help that Wall Street dissed the results. Investment banks Wells Fargo, J.P. Morgan, and Truist all cut their price targets on Dollar General stock after its report. But today, Bank of America is having the opposite reaction, and double-upgrading Dollar General stock from underperform to buy.

Is Dollar General stock a buy?

BofA highlighted improved customer satisfaction surveys (up 9%) alongside better inventory management, predicting sales will keep improving at Dollar General, and perhaps profits, too. And BofA may be right.

Turning to guidance, Dollar General narrowed its forecast for both sales growth (4.8% to 5.1%) and earnings ($5.50 to $5.90) growth this year. At the top of that range, Dollar General stock would be selling for about 14 times current year earnings, which doesn't seem expensive. Moreover, free cash flow year to date is $1.2 billion, putting the company on track for perhaps $1.5 billion through year-end.

That's a price-to-free-cash-flow ratio of less than 12. For a stock paying a 3% dividend yield and growing even in the mid-single digits, it might be cheap enough to buy.