I just came across a topic about a legend in the Japanese stock market, and I couldn’t help but want to chat with everyone. Two “god-level” figures have emerged from Japan’s trading circles: one is BNF, acclaimed as the “god of trading,” and the other is the strongest retail trader, CIS. What’s interesting is that these two aren’t just longtime friends—their experiences are also eerily similar.

They both started trading as early as their university days, gradually accumulating from small capital into a trader managing positions at the scale of hundreds of millions. What leaves the deepest impression is that famous J-COM mistaken order incident. That day, CIS pulled in 600 million yen, while Takashi Odaka (BNF) was even more aggressive—he earned 2 billion yen in just 10 minutes, which was about 150 million RMB at the exchange rate at the time. Operations at this level are practically legendary in Japan’s conservative trading community.

What’s most valuable is that both of them, unusually, shared their own trading thinking. Takashi Odaka’s trend-following strategy and CIS’s trend-following principles later became subjects of study and application by countless traders, and they still hold practical meaning even today.

When it comes to Takashi Odaka’s approach, we need to start with his early contrarian investing. Between 2000 and 2003, the internet bubble burst. Global stock markets turned bearish, and Japan couldn’t escape it either—investors were generally pessimistic. But he saw an opportunity others couldn’t: in a bear market, asset prices often deviate significantly from their real value. By observing the 25-day moving average divergence rate, he identified stocks that were severely undervalued and seized the opportunity during the rebound. This method helped his account grow from small beginnings to 100 million yen.

Specifically, if a stock’s 25-day moving average is 100 yen and its current price falls to 80 yen, the divergence rate is -20%. When the divergence shows a large negative value, it means the price is severely undervalued—this is the buying opportunity. Different stocks and industries set different divergence baselines, and that was an important reference for his entries.

In 2003, as the Japanese stock market began to rebound, Takashi Odaka’s strategy changed as well. He shifted from picking up bargains to following the trend. This transition caused his assets to surge from 100 million to 8 billion yen. He liked doing short-term trades lasting two days and one night. In a single day, he would hold 20 to 50 stocks at the same time, reducing risk by diversifying his positions. He was especially skilled at leveraging industry linkage effects—for example, within the “four major” steel companies, if one company rose, he would immediately buy the other three that hadn’t risen yet, so he could ride the entire industry’s upward wave.

CIS’s trend-following principles offer another perspective. He believed that stocks rising consecutively are likely to keep rising, and stocks falling continuously are likely to keep falling. Most people treat stock price moves like a 50/50 probability game, but the market itself has strong continuity. When a stock performs strongly, it draws in more capital, making the strong even stronger. We should accept the market’s power rather than fight against it.

Many people like buying when prices dip, thinking they can catch the bottom—but in strong bull markets, this idea often makes you miss the entire run. The same goes for adding to losing positions; that should also be avoided. Admitting you were wrong and cutting losses quickly is the correct approach—not that you can’t lose money, but that you need to achieve small losses and big gains.

CIS also emphasized one very important point: don’t blindly worship past rules. The market is a complex, dynamic system. Once so-called golden rules are widely circulated, they often become ineffective quickly. Truly great traders often emerge during stock crashes, economic crises, or market turning points. When the vast majority of people fall into panic, the market brings huge volatility—and the greater the volatility, the more opportunities there are. This is precisely the moment when a small number of people who can stay calm and act decisively rise to the top.

In short, trading involves risk, and entering the market requires caution. I hope these insights from trading predecessors can inspire you.