Everyone is allowed to trade. There is no rich or poor status in investing. And there is no minimum amount of investment. The only difference is that the rich have higher buying power while the poor have limited resources. But both can invest and may change their life.
If you are talking about this market when you say that there is no minimum amount to become part of it you are right, but if you are talking about other markets then you are wrong, many other markets have minimums that you need to invest which is why there is a barrier to entry and if you want access to the best opportunities that are out there then you need to have a lot of money already, governments do in fact do everything they can to stop people from participating in the markets supposedly because they are trying to protect you but they are instead interested in protecting the rich and their profits.