If I have a live account which has, say $10,000 in it and I call this method

 public override void Initialize()
{

    // cash allocation
     SetCash(5000);

}

and in my algorithm I call:

    SetHoldings("SYMBOL", .33);

What would the order do? Would it order 0.33*$5,000 or 0.33*$10,000 since that's the total cash in the account. Also, say it sold and the cash increased from $5,000 to $7,000 (with a total cash balance of $12,000) would again be 0.33*$7,000 or 0.33*$12,000? 

Thanks and best regards