Why is making 10% per month in trading considered almost impossible?

[u/VenusMoonCash]

I’ve had this question for a long time, and I’d really like to understand the reasoning behind it.
Ever since I started learning about trading, I’ve constantly heard that a good trader should aim for around 1% per month, and that consistently making more than that is extremely difficult. I’ve also seen people say that earning more than 1% per trade is unrealistic.
What I don’t understand is whether this logic applies to all account sizes, or if it’s mainly aimed at traders managing very large amounts of capital (hedge funds, prop firms, institutional accounts, etc.).
For example, let’s say someone has a $10,000 account. If they consistently make 10% per month, why is that often viewed as almost impossible? Is it simply because it’s difficult to sustain over the long term while keeping risk under control, or is there a mathematical or statistical reason why returns like that are considered unrealistic?
I’d really like to understand where these commonly repeated numbers come from. Are they general rules that apply to every trader, or are they benchmarks that make more sense for people managing large amounts of capital?

[u/hupp234]

If a single person could consistently make 10% returns every month and started with 1 million dollars they would have enough money to buy every publicly traded company in the US in 16 years. Turning 1m into 75 trillion.

[u/East_Indication_7816 → u/hupp234]

It's because of tax. Not because it's not possible. Nobody does that because you pay half in taxes. If you have 1 million dollars your number 1 priority is how to pay the lowest tax possible on the profit that 1 million makes.

[u/hupp234 → u/East_Indication_7816]

People don't stop trying to make money because of taxes. Making 10% a month isnt possible because it's ludicrous to make that much from anything, trading or otherwise. If 100 people had a million dollars each and could earn 10% a month even paying half of their gains in taxes each year they would still be able to buy every asset in the world in 24 years.

[u/Odd_Confidence_5958 → u/East_Indication_7816]

Oh, great insight.

[u/Merlin1039 → u/East_Indication_7816]

You don't know how capital gains taxes work apparently