There are two legendary traders in the Japanese stock market. Their stories have been passed around in the trading community to this day. One is the widely known trading god BNF, and the other is the strongest retail trader, CIS. Their years of friendship and similar growth paths are truly impressive.

What’s most memorable is the J-COM mistaken order incident. On that day, CIS made a name for himself by grabbing 600 million yen, but BNF was even more incredible—he earned 2 billion yen in just 10 minutes, which was about 150 million RMB at the time. This level of execution isn’t based on luck; behind it is a deep understanding of the market.

Koikawa Takashi (BNF’s real name) didn’t achieve success overnight. In his early years, he mainly built his fortune through contrarian investing, especially in the years following the burst of the internet bubble in 2000. At that time, global stock markets were bearish, and the Japanese market was dragged down as well—most investors were pessimistic. But he found an opportunity: even though stock prices would keep falling in a bear market, they would also come with rebound after rebound. He profited by catching these rebounds.

His method was very specific—watching the deviation rate of the 25-day moving average line. When a stock’s price deviated significantly from the 25-day line—for example, if the line was at 100 yen but the stock price was only 80 yen, giving a deviation rate of -20%—he believed the price was severely undervalued and worth buying. Conversely, if the stock price was too much higher than the line, he would be wary of the risk. This approach helped him accumulate from early small capital all the way to 100 million yen.

The market environment changed in 2003. As the Japanese stock market entered an uptrend, Koikawa Takashi also changed his strategy. He was no longer just picking up bargains; he began to trade in line with the trend. This shift caused his assets to surge to 8 billion yen. His day-to-day trading had distinctive features: he did two-day-and-one-night short-term trades, while holding 20 to 50 stocks to diversify risk. After taking profit or cutting losses each day, he quickly switched to new targets. He was also especially good at leveraging industry linkages—for instance, among the four major steel companies, if one of them rose, he would buy the few that hadn’t risen yet.

CIS’s trading thinking is simpler and more forceful. His core conviction is: stocks that rise consecutively will most likely keep rising, and stocks that fall persistently will most likely keep falling. It sounds simple, but most people just can’t do it. Many people, seeing a stock rise for a while, get afraid of buying at the high point; instead, they wait for it to drop and buy later. As a result, they miss the entire upswing cycle in a strong bull market. He believes the market has a strong continuity—strong stocks will get even stronger, weak stocks will get even weaker. We should accept the market’s power rather than go against it.

He also emphasizes one key point: don’t add to a losing position. When a trade starts going against you, the smartest move is to admit failure and cut losses quickly. Many people instead increase their bets, which only makes the losses grow bigger. What truly matters isn’t the win rate, but overall returns—getting small losses with big gains is enough.

Both legends are stressing one thing: once market rules are widely spread, they stop working. Trading requires a unique perspective and sharp judgment. Truly excellent traders often emerge during stock crashes and crises. When most people fall into panic, it’s precisely in those moments that the few who can stay calm and take decisive action stand out. The higher the volatility, the more hidden opportunities there are.