Most individual investors, in Vietnam or eleswhere, do not understand some of the very basic investment principles. They tend to trade way too often and to not pick the right stock. But the less conscientious investment managers do not much better and sometimes assume that as long as a stock stacks up well in terms of Price to Earnings, it represents an attractive investment. Price to Earnings is only a tool, a tool that must be used with a combination of other ones. Analysts must consider, accounting rules, Cash Flows, ratios but also managers motivations and dynamic of the organization. If you fail to do that you will fail as an investor.