每日钉一下（投资股票基金，有人赚钱就一定有人亏钱吗？）

Group 1 - The article highlights that most investors are familiar with stock index funds but have limited knowledge about bond index funds and their investment strategies [2] - It emphasizes that investing in stock funds is not a zero-sum game, meaning that it is possible for all investors to make money in the long term if investments are managed properly [5] - The concept of a zero-sum game is explained through gambling, contrasting it with stock fund investments, which are described as a positive-sum game where all participants can benefit [6] Group 2 - The article mentions that the long-term profit growth rate of A-share listed companies is around 10% annually, indicating a potential for sustained returns in stock investments [6]