Tell your brother to finish college, enjoy life and and don't worry about what you're doing. Any good luck he may experience now will not serve him later on like a college degree. If you were older, you would understand what I mean by the phenom $90,000 for a year "burger flipper" doing web development in the last tech boom. These things are cyclical.
Help him finish his degree, help him get his own good job and plan a career with good prospects that will serve him in this boom, or any other. I dropped out of high school to program for a living in 1988, so I'm not suggesting he does what I did.
It isn't a competition and since history repeats itself, just like economic cycles, he'll have a chance again. We had a good boom then, in the nineties and again the last couple of years. But at 21, I wouldn't listen to sage advice either.