On February 19, US Treasury Secretary Yellen stated that Bitcoin is a highly speculative asset. She pointed out that Bitcoin has been highly volatile in recent years. When asked if he thinks supervision is needed, Yellen said that any action must be related to protecting investors. She said that I think it is important to ensure that it is not used as a means to trigger transactions and that investors are protected. Therefore, I think it is of course important to supervise Bitcoin trading institutions and ensure that they comply with their regulatory responsibilities.