A major prerequisite for building a system is that liquidity is sufficient. But the “death” of a system in the long run may last even longer—for example, the technical analysis we use is based on human social group activities and psychological activities. However, if the number of participants in a particular market or a particular asset is too small, liquidity will be extremely poor. In that kind of market, such a market does not have the conditions for using technical analysis, and any trading system derived from technical analysis will be in long-term death in such a market. Similarly, if most listed companies’ financial statements are falsified, then fundamental trading systems that use financial statements to observe the value of listed companies will also be in long-term death.