每日钉一下（经济火热时，适合投资吗？）

Group 1 - The article emphasizes that many investors start their investment journey with index funds [1] - It introduces a limited-time free course that covers investment techniques for index funds [2] - The course offers additional resources such as course notes and mind maps to enhance learning efficiency [3] Group 2 - A call to action is provided for readers to add a course assistant and reply with "index fund" to receive the course [3] - There is a suggestion to click on a link to access a free family asset allocation course [4]