This book was reorganized by adding, for example, post-hoc comments on the articles in the investment blog "Investing in Emerging Countries" (https://invstem.com).Originally written in Japanese, I translated it into English.As short as possible, the amount of time that can be read out is as much as possible."Investing in Emerging Countries" blogs focus primarily on emerging market trends, but we also sometimes focus on specific themes, as in this book.In this report, we summarized the trends in the crude oil market, especially in shale companies, in one book.I thought it would be better to put it together as a single e-book than to put it on a blog. We hope that this report will be used to review the past.The crude oil market is indispensable in considering the global market.In discussing the crude oil market, shale oil trends cannot be ignored.In particular, in 2019, the U.S. became an exporter of crude oil, and shale oil was perceived as a game changer. In 2020, however, crude oil prices fell sharply due to the corona shock and other factors, and many shale companies faced difficulties.It may not be directly related to investing in emerging countries, but it is also a very interesting topic from the viewpoint of investment.In this book, we have reorganized the content of the blog so that the dates and times are in order from the older ones, and we have also re-edited it by adding some post-hoc comments.Therefore, the content of this report is based mainly on the chronological description of the reported facts, and it does not provide detailed analysis or evaluation of each event or fact.Details are also included.There were many events and news that were meaningless from a later perspective, but I think it would be better to understand the atmosphere and situation at that time by including these events and news.As mentioned herebefore, this book is not something like advising or teaching direct investment decisions, but rather a tool for re-organizing past events and understanding and recognizing them to a certain extent.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~As mentioned herebefore, crude oil sometimes expresses the market sentiment of the time with an excessive manner, so I think it is very useful to look at the movements of crude oil, with exception to whether or not it is actually invested into.Once the investment and investment-related news is reviewed in chronological order, you may find that you are aware of a variety of issues and that you are aware of future investment policies.We would appreciate it if you could find out on this occasion.