It is bright and early Saturday morning within the sleek brick contours of the Gran Provision supermarket. Women in white smocks are pecking at electronic cash registers. Stock boys are weaving down aisles with cartons and price markers.

All the while, and to no one's surprise, panic buying is under way at nearly every counter and shelf. Families of four are stocking up with 80 pounds of sugar and two dozen liter bottles of soda and mineral water. Others are hauling unopened cartons of canned goods and cookies to their cars.

The mass spree is as natural for these shoppers as their warped economy is wild. For this is the first weekend in a new month, and the middle-class shoppers of this downtown neighborhood are engaged in what has become a desperate national sport -- trying to outrace the 600 percent inflation.

"No one can afford to hold on to their paychecks," explains Claudio Reynolds, a kiosk vendor. "You get your monthly paycheck and you buy everything you can, because you know that every day, the prices are going to go up."

Argentines who shun such peculiar habits risk quick financial ruin. A peso left unspent and unprotected lost about 22 percent of its buying power in the 31 days of August. Inflation in the 12 months before August was 615.6 percent, the highest rate in the world.

Adaptation to this kind of price spiral has made Argentina a wonderland of speculative innovation and fantastic distortions. It is a place where sober middle-class professionals prefer stuffing dollars under mattresses to depositing any currency in a bank; where landlords demand 18 months' rent in advance for an apartment; where mortgages and installment payments are virtually nonexistent; and where the cardinal rule is to unload the national currency as quickly as it falls into your hands.

As in some twisted, circular game of national hot potato, the big losers in Argentina are the ones left holding the cash. Nineteen pesos equaled a dollar here nine months ago. Now the official exchange rate is 70 pesos to the dollar, and consumers who actually want to buy U.S. currency must pay 110 pesos to the dollar on the illegal black market.

Not surprisingly, government polls here show that inflation is now the first concern of Argentina's 30 million people, way above the foreign debt or politics. Increasingly, the price surge has also become the principal threat to the nine-month-old government of President Raul Alfonsin. Alfonsin has tried wage and price controls, cutbacks in the government deficit and curbs on monetary expansion to stop inflation.

Yet, fed by rising salaries, the collapse of business investment and its own reckless momentum, inflation has steadily risen this year.

"We economists can't really even explain it any more," said Anibal Martinez Quijana, a researcher at a local foundation. "Every sector is trying to beat out the other; if one sector raises prices by 20 points, the other goes up by 40. It's an addiction."

The new democratic government's problem is compounded by inflation's institutionalization in Argentine society over the past 40 years. In the last decade, Argentina has had an annual inflation rate of less than 100 percent only once, in 1980. Between 1970 and 1980, prices increased by an astounding 282,000 percent. Between 1950 and 1980, the total inflation was no less than 24 million percent.

In contrast, accumulated U.S. inflation in those same three decades was 242 percent, while in Mexico prices rose only 1,100 percent.

"We have developed the most sophisticated mechanisms for inflation in the world here," said a rueful Argentine banker. "Everyone here knows how to speculate; everyone is an economist."

For thousands of Argentine consumers, the first rule of economic survival is to use every extra peso left over from monthly shopping sprees to buy dollars. By holding extra cash in U.S. currency, consumers can usually keep even with inflation as the price of the dollar rapidly escalates against the peso on the booming black market.

"There are probably enough dollars under mattresses and in foreign bank accounts to pay the $43 billion debt," said the local banker, who asked that his name not be published. "The only one in Argentina who doesn't have dollars is the Central Bank."

In contrast, depositing earnings in a bank savings account is dismissed by many Argentines as sheer folly. One hundred pesos deposited in a savings account here in January would now have increased to 257 pesos through interest payments of up to 15.5 percent monthly. But the buying power of the money would have dropped by about 30 percent in the endless escalation of prices.

For more enterprising investors, buying dollars is only the beginning of the inflation game. Handsome profits are to be made by leaping on to the ever-more-rapidly spinning wheel of money whizzing through the economy and its financial and commodity markets -- if one can only leap off at the right time.

"A smart investor is constantly shifting his capital from place to place to ride the price increases," said the banker. "He goes from the dollar to the stock market, the next day he sells the stocks and buys bricks, and the week after that he sells the bricks and lends in the intercompany loan market at 22 percent interest. Then he collects his loan in a month and goes back to the dollar. It all goes in a big circle, faster and faster. If you sleep 10 hours, you lose."

Even the smallest businessmen tend to be wondrously dexterous in byzantine speculative maneuvers. Take Claudio Reynolds, the 29-year-old operator of a small kiosk selling candies and cigarettes downtown. Reynolds arranges to buy a good part of his week's stock each Saturday from a supplier at one fixed price, but pays him in seven installments, one each day of the week.

Reynolds has the money to pay the supplier in full on Saturday, but instead of doing so uses the excess pesos to buy dollars. Because the peso drops in value almost every day, each day Reynolds has to reconvert fewer of the dollars he bought to meet his fixed peso installment.

"By Tuesday," he said, "I'm effectively paying 19 pesos for something that cost me 20 on Saturday." In the meanwhile, he is charging his customers more, because his own prices are rising.

"That," he said, "is how I survive."

Any possible delay in fixed payments -- no matter how small -- is used by Argentines to gain a small margin. Consumers with credit cards make all their purchases on the first and second days of the month, knowing that the real price of what they buy will effectively come down by 20 percent, the rate of inflation, by the time they receive their bills at the end of the month.

The ones who get hurt, say economists here, are working-class wage earners who have neither credit cards nor extra pesos to speculate with. Salary increases are granted monthly, and the government has followed a policy of raising wages above the inflation rate. The official figures, however, now work only on paper; workers granted a 4 percent increase over inflation in July saw their gain evaporate in the first week of the next month's zooming prices.

All of the speculative maneuvering and indexing, say economists, only helps feed new bursts of prices. The rises are now so rapid that consumers and businessmen are frequently left bewildered, unable to keep track of what even basic goods should cost.

Jose Arrivas, the manager of a small convenience market, understands the phenomenon. So far this year, he has received 311 new single-spaced lists of price changes from his chain's headquarters, or an average of 1.3 per day. Every day, Arrivas says, he changes a price 100 to 150 times.

"People have lost all concept of prices," he says. "They come in here and see whiskey selling for 150 pesos and they say, 'But I saw it just yesterday down the street for 145.' So they go back down the street, only the price down there is now up to 154.

"The result is that people just pay whatever price they find, because they just want to get rid of their money and they know the price is going to go up. Nobody can cope. It's a system gone mad."