What age?

I am 13 and I just started. Figured I might as well since I have 5 years ahead of me of being financially dependent.

You can't really trade until you've reached the age of majority.

However, if you're asking whether people have started looking into the stock market prior to that age, then yes, some people have started as early as 15; just reading into and researching stocks.

What age?

I am 13 and I just started. Figured I might as well since I have 5 years ahead of me of being financially dependent.