Well, the law regarding interest on short payment of advance tax was brought mainly for businesses.
Most taxable incomes gets covered under TDS, so this TDS partly reduces the advance tax burden on such incomes. But profit from trading and capital gains have no TDS. so the burden is transferred to the individual to calculate the amount of advance tax to be paid.
It is a general assumption that any business should be in a position to reasonably estimate its revenue, expenses and profits to some extent.
Trading is a unique business/profession, that being said, if one wishes to avoid interest on short or delayed payment of advance tax, rather than paying nothing, some amount of advance tax can be paid for each quarter to avoid this penal interest to some extent.
As the year progresses, we might be able to adjust the advance tax payment based on the status in the current quarter. So even if u pay more in Q1, you can re-estimate it in Q2 and pay accordingly.
The problem arises only when u have losses in say first 2 quarters, but make huge profits in the next 2 quarters.
Now even though u had no taxable income in the first 2 quarters due to the losses, since your final tax liability at the end of the year will be more, you will be charged interest for such short/non-payment, if u miss to pay advance tax for Q1 and Q2. This although seeming unfair, is unavoidable.
Traders & investors: There’s a misconception that traders and investors can pay advance tax at the end of the financial year. In reality, it’s a quarterly obligation. Profits from trading or capital gains must be estimated and paid in instalments.