Hajime Mabuchi is an early riser. After sobering up in a hot Jacuzzi at his home in a Seattle suburb, he takes some vitamins and drives to a nearby Starbucks coffee shop. He arrives at 6 a.m.

There the 52-year-old opens his laptop, connects to an online stock-trading site via the Internet, and starts trading Nasdaq stocks at 6:30 a.m. — 9:30 a.m. New York time. He stays fixed to the computer screen and fires away buy and sell orders, all executed immediately with a click of the mouse.

Every second matters.

Usually by 9 a.m., Mabuchi reaches his target of the day, say $500 in profits, and he cruises down an empty highway home.

This is the kind of lifestyle the ongoing revolution in stock trading has created, says Mabuchi. He is probably among the first Japanese to join the day-trading bandwagon that has swept across the United States in the past few years.

Experts say that the day-trading boom epitomizes how technology has given regular investors a tool to challenge, or even topple, theoretically, Wall Street pros. The same kind of revolution might strike Japan, where the first-generation of online trading is just taking off.

Although largely an obscure concept in Japan, day-trading is gaining a rapid following from a small group of Japanese.

Day traders say that the software they use makes the big difference. They show real-time “bid” and “ask” offers — buy and sell offers — being made by a dozen brokers, not just one. Individual traders can execute their orders in a split second with any of the brokers displayed on their computer screens.

Studies show there are 4,000 to 5,000 full-time day traders in the U.S. If part-timers were included, the day-trading population would be a few million.

Last fall, Mabuchi and his two American partners set up their own firm, tying up with a U.S. trading school. In less than six months, about 100 Japanese people have attended Mabuchi’s three-day seminars, each paying 290,000 yen, excluding air-fare and accommodation.

But this rosy scenario does not work for everyone. Some experts are more than skeptical of the idea that an amateur trader could strike gold in capital markets.

In the U.S., skepticism was further fostered last July when a 44-year-old Atlanta man went berserk after losing his money day trading and fatally shot nine people at a local day-trading firm after killing his own family.

The North American Securities Administrators Association, Inc., a group of securities regulators across North America, also released a report questioning the industry last summer.

The report cited an analyst who studied accounts and concluded that “70 percent of public traders will not only lose, but will almost certainly lose everything they invest.”

But day trading proponents — including Omar Amanat, a chief executive officer of a day-trading firm — disagree.

The 27-year-old technology wizard, who co-founded Tradescape.com in May 1997, expressed disgust over the analogy of day trading to gambling. What day traders are doing now — scalping profits from short-term ups-and-downs in the markets — is nothing new, he said.

“Short-term investing is something that people have been doing for a while,” he said. “But it’s different. If you call them stock market professionals they are not gamblers. If they are individual mom-and-pop traders, then it’s all said (to be) gambling.

“And what else is this institution other than a collection of individuals?”

Day-trading advocates also argue that conventional brokerages, which have long spurned the day-trading industry, have recently awakened to business opportunities they might be missing out on.

“They are realizing now that active trading is not going away, that the group of active traders is growing steadily,” said Tim Bourquin, an LAPD police officer-turned-day trader who organized an online trading expo in New York in February. “So they are finally reaching out, trying to provide services for them, because they know if they don’t, somebody else will.”

Bourquin cited a February acquisition of the major day-trading firm CyBerCorp.com by Charles Schwab, the world’s largest online brokerage, as an example of how lines between traditional securities houses and day trading firms are blurring.

In Japan, few people even know what day trading is. And despite all the hoopla over information technology these days, experts say that major legal hurdles must first be cleared for day trading to catch on here.

Sadakazu Osaki, head of Capital Market Research Unit at Nomura Research Institute, said day trading has spawned in the U.S. partly because individuals with a small amount of cash at hand can repeat trading by using profits gained to buy another batch of shares within the same day.

In the U.S., for example, if someone buys shares worth $30,000, and manages to sell them for $60,000 an hour later, he can use the $60,000 to buy another batch of stocks on the same day. It remains unclear whether such practices are permissible under Japanese regulations.

Unless specific rules are set, Osaki said, “We will not have the kind of day-trading boom experienced in the U.S.”

Meanwhile, some risk-loving Japanese are already trading Nasdaq stocks like U.S. day traders do, connecting to U.S. day-trading sites via the Internet.

Yasuyuki Takada is among the first Japanese to start a U.S.-style day-trading company in Japan. After 15 years as a technology analyst with Intel, he quit the job last summer to become a full-time trader.

He has had his ups and downs: Since he started trading last July, he has suffered a $16,658 loss one month but gained $27,190 in another.

Late last year, he set up his own company, DayTrading Systems, to teach people how to trade, signing an agreement with a major day-trading firm in the U.S. to use its trading software.

Takada is unfazed by legal hurdles hampering U.S.-style day trading in Japan — he goes around them.

“Why bother looking at Japanese markets when Nasdaq provides all you need for direct access trading?” he asked. “Trying to change laws or to fight an industry practice in Japan is a waste of energy.”

While people like Takada remain a minority here, there are signs that more people will start bypassing the Japanese securities industry to trade directly on U.S. capital markets.

Toshio Sakai, 29, organizes the Japan chapter of DayTraders USA, an association of day traders in the U.S. The group’s mailing list has 3,900 subscribers, ranging from a 16-year-old who proclaims he will make 100 million yen in three years, to retirees in their 70s who are curious about the latest trend in the U.S.

Major travel agency H.I.S. Co., which has a securities company under its arm, opened a trading school last November targeting individuals. One of the courses lets people practice direct-access trading from Japan.

Sakai said his group plans to hold an expo later this year to educate people about day trading. Some 10 to 15 trading firms both from the U.S. and Japan are expected to participate as exhibitors, he said.

“True, day trading is like a game,” Sakai said. “But individuals who play the game are not taking money away from individuals. They are taking money away from big securities companies.”