1). is to use 1$ for one index point and that's for 1 contract.

2). people can specify the no. of contract they bet...

3). introduce margin requirement.
however, the no. of the contract should <= current huasing point/100. this serves as the margin purpose. assume for each contract, you need to have 100 huasing $.


buy contract 10 at 2300.
account huasing $ 1000. my max position size is 1000/100= 10 contract.

1) assume sti goes up and ends at 2400 when i close the position. profit is (2400-2300)*contract size = 1000. en, pretty good return.

2) if index goes to 2200. loss is 1000 too.

3) special case. when margin -> 0, someone goes bankruptcy and have to close the position... where, since we are talking about finance, there is always risk with return. you get to know the leverage risk in index future trading....

my two cents...
the no. is for demo. we can discuss the margin/contract.

or extendible.

build the position, and close the position whenever i think appropriate as long as my margin requirement is fullfilled.