With straddles, timing is everything. If you get a $20 move quickly, you make 4-6 pts. If it takes a few weeks, you lose money. Add an IV contraction and your timing had better be very good.
If you do more than 3 margin day trades in 5 market days and the # of them is more than 6% of your total tradies in that time period then you're designated a "Pattern Day Trader" and must have 25g of equity in your account. Google "Pattern Day trader" for add'l info.