Let me clarify few things about tax audit.
Tax audit is attracted in the following cases.
If your income is less than 8 or 6% of the actual turnover then you may go for a tax audit.
if your income is more than 8% of your turn over you may not get your books of accounts audited.
Now the transactions involving speculation futures and options are considered as business income which means trading is considered as business and hence tax audit will apply.
A tax audit may apply if your turnover is more than 2 crores this is mandatory provision. Or I said earlier if your income is less than 8 or 6% of your turn over.
the calculation of turnover is tricky however I believe zero does provide you to understand what is the quantum of your turnover that is eligible to be called as a turnover as per Income Tax Act.
if you are in losses which means your income is less than 8% of 6% you must compulsory get your books of accounts audited by chartered accountant for carrying forward the losses.
Whether or not you get your books of accounts audited in which case you must compulsory disclose income higher than 6 or 8% do you may not have actually earned it. The taxmann requires you to pay taxes on the percentage basis that is presumptive basis and not on the actual income earned