每日钉一下（想判断市场便宜还是贵，如何轻松搞定呢？）

Group 1 - The article emphasizes the importance of index funds as a starting point for many investors in their investment journey [2] - A free course is offered to teach investment techniques for index funds, including course notes and mind maps for efficient learning [2] Group 2 - The article introduces a method called "screw star rating" to assess whether the stock market is undervalued or overvalued [7] - A 4-5 star rating indicates that the market is generally undervalued, making it suitable for investing in stock funds [7] - Ratings below 4 stars suggest that investors should hold their positions, while ratings of 3 stars and above indicate potential overvaluation, prompting consideration for selling to take profits [7]