Stocks logged major declines on Friday, with the Dow Jones Industrial Average (^DJI 0.06%) and the S&P 500 (^GSPC -0.22%) indexes both falling by more than 2%.

Today's stock market:

Index

Percentage change

Point change

Dow

(2.1%)

(394)

S&P 500

(2.5%)

(53)

Source: Yahoo Finance.

Investors' concerns are growing that a second interest rate hike by the Federal Reserve could come as soon as this month, following the central bank's September monetary-policy meeting. Some Fed officials appear to be leaning toward raising rates, given strengthening economic data, and that debate seemed to contribute to the market's most volatile trading session in more than a month.

Meanwhile, a few stocks bucked that overall downtrend. Companies making notable gains on Friday included Kroger (KR 0.56%) and National Beverage (FIZZ -0.40%).

Kroger's slowing sales growth

Kroger shares rose 1% after the supermarket chain announced a sharp growth slowdown for its fiscal second quarter. Comparable-store sales fell to 1.7% from 2.4% in Q1. In contrast, comps had been steadily above 5% for nearly all of 2015:

Data source: Kroger financial filings.

Like many other industry participants, Kroger's numbers were pulled down by food-price deflation, which is hurting the grocery business for the first time since 2009. Average prices fell by nearly 2%, executives said. Since the depth of that drop was a surprise, and because management expects deflation to persist at least into early 2017, Kroger lowered its sales and profit targets for the year.

Still, the company managed to improve the key operating trends that drive its long-term results. Sales volume, customer traffic, and market-share levels all improved this quarter. Meanwhile, management said that their big picture financial goals are unchanged. "Our growth objectives are on a three to five year rolling cycle, and we remain confident in those targets," CEO Rodney McMullen told investors in a conference call.

Perhaps reflecting that confidence, McMullen and his team lowered their 2016 capital spending plan by $500 million, and suggested that the company instead will direct those funds toward repurchasing shares, which have fallen by 20% so far this year.

National Beverage's surging volume

National Beverage, the company behind Rip It energy drinks and LaCroix sparkling water, saw its stock jump 4% following its 10-Q filing with the Securities and Exchange Commission. That report contained greater detail on its blockbuster first-quarter report, which a late August press release described in only general terms.

Image source: National Beverage.

Investors already knew that sales growth improved, but Friday's filing showed that volume growth more than doubled, to a 20% pace compared to the 9% gain that National Beverage managed in fiscal 2015. Executives said nearly all of that increase was powered by surging demand for its sparkling-water portfolio.

In addition, these products tend to carry higher margins, and that favorable trend combined with falling commodity costs sent the company's gross profit higher, by 36%. As a percentage of sales, gross profit margin soared to 39% from 34% a year ago.

Altogether, this filing adds weight to management's claim that National Beverage is especially well positioned to capitalize on the trend toward healthier drinks. Its products are clearly resonating with customers, and that success is pushing sales and profitability to new highs.