Double bottom is a kind of bottom form. The letter "W" in this shape generally means that when the market is in a downturn, if investors only judge whether to buy from the volume, they will easily make the mistake of bottoming out, because after a long-term decline in the stock index, the kinetic energy of shorting in the bottom area will be close to exhaustion. Because most retail investors cut meat when they fall, most chips are in the hands of the main players and appear in the bottom area. Looking back at the adjustment of 1997- 1999, we first touched 1025, and 1998 rebounded to 1422, but it fell back to1022 on August 2. However, every double bottom and triple bottom triggered a strong rebound. We will also find that only a small amount of trading volume can be pulled out of Yangyang, giving people the illusion that this is just an oversold rebound, because the main force has not gone in and is still waiting for heavy buying. Most investors found that the trading volume could not be released after cutting the meat before, and they were afraid to buy it easily. When the stock index keeps rising, the funds coming out will wake up like a dream. In fact, the concentration of chips in the main force is very high at this time, and it does not need a lot of trading volume to pull individual stocks and the broader market, and the trading volume will continue to enlarge, and the risk at this time is also increasing. Personally, I would like to emphasize that the market in the second half of 20 1 1 is still the idea of applying bands. But this is also the middle and late stage of reaching the rebound or band market. The way to success is to buy in the amount of land, and continue to throw high after the amount of land increases. However, people will doubt how high the rebound can be. Under the trend of integration, people are worried about the full circulation of state-owned legal person shares, stock index futures and secondary market, the merger of A shares and B shares, and the issuance of large-cap stocks. The basic factor affecting investors' confidence is the theoretical trend of thought in line with international standards. In fact, investors feel that the prospects are bleak, and they dare not make a big determination to do more, only doing short-term speculation. Because of this, the hot spots of rebound are short-lived. Suggestion: From the analysis of technical indicators alone, there is no golden cross between macd indicator line and kdj indicator line on the 60-minute chart of the market, indicating that it is difficult to continue to rise in the short-term rebound for the time being; The 3-day moving average (3,820 points) and the 5-day moving average of Shanghai stock market turn their heads downwards respectively, which suppresses the rebounding stock index; Therefore, it is considered that before the market index breaks through today's low, there is a chance of rebound between the 3-day moving average and the 5-day moving average, which can be thrown high in the short term.