oes not prove a record of consistency. But a return of 100% in any one year is still a great achievement.
No need to wait a year, with a 100:1 leverage (like in Forex) a trader can make 100% in a few seconds, after the Non-Farm Payroll or some other important financial report.
And then he could brag all about it at his local bar, between two cold Heineken.
But making that consistently, that's another story.
to double $1 every year for 20 years (for a grand total of $40),
Well, if you double a dollar every year for 20 years, you will end up with $1,048,576