Lol, there's are traders out there with better records than buffett e.g.
Soros 30% plus for 30 yrs
Druckenmiller 30 % plus for 30 yrs
Peter Brandt 40% for 25 years
If one can say 30% for 30 years, he should make
1.3^30 = 2619.996 times.
40% for 25 years, he should make
1.4^25 = 4499.88 = 4500 times.
To compare those performances equally, let the length of investment be 50 years (from 30 to 80).
For 20%, 1.2^50 = 9100.438 (100K becomes 910M)
For 30%, 1.3^50 = 497929.2 (100K becomes 49792M)
For 40%, 1.4^50 = 20248916 (100K becomes 2024891M) which is bigger than small country's wealth
Note that stock market kept open for 400 years from Netherland. If there WAS any one with 20% outperformance trading logic, then he has all the wealth on earth NOW. Even Buffet and Gates should be broke now.
Therefore, I am sure no one HAD 20% logic for 400 years.