If someone chooses to invest 9% of his savings, this is really not an ideal way. Because investing using 9% or 3% of his savings is not an ideal way or the right decision. You can invest 9% from the amount of money you have left after excluding personal expenses, housing expenses, all kinds of expenses. If you invest in this way, then even if your investment loses money immediately, you will not be very upset. Because you are investing after meeting all your needs. For example, you are investing with the amount of money you do not need, so even if you face immediate losses, you will not be too worried.
How can you call it a wrong decision for an investor to invest 9% or 3% of his income? Daily expenses are certainly important. But if there is a prudent source of income, an investor can safely invest 9%. Because, 70%-80% of the prudent source of income may be enough to meet daily needs. If someone plans to invest 9% of the remaining 20%-30% of the money, then I do not see anything wrong with that. Although everyone's income and expenses are not the same. If you are unable to meet your daily needs with 70%-80% of your income from your income source, then it may be a bit risky for you to manage your investment with that source of income. If more than 85% of your income is spent on meeting daily needs, then I think your source of income needs to be upgraded for investment.
Because from the remaining money, you not only need to invest but also have a backup fund ready and sufficient cash flow. For this, I think it is important to have at least 15% of your income left for investment. Having more than 20% of your income remaining may be ideal for investing. So if investing 9% of your income is a bad decision, then your income source may not be prudent. In this case, I disagree with you.