How muh margin a broker (Ameritrade, Scottrade, Zecco) gives for a $100K cash account?

Question

How muh margin a broker (Ameritrade, Scottrade, Zecco) gives for a $100K cash account?

Answer 1

it will be  $ 200,000

but do not be over this amount  in the end of the day.

you need to cover the amount .

or they will sell your stocks to cover the different

Answer 2

$200,000 standard margin with $100,000 cash deposit or fully paid marginable securities.

$400,000 day trading margin (must close positions at end of day if margin is over $200k)