Purification refers to removing any non-permissible income that may be earned from your stock investments. There are a few common methods:
Dividend purification method: Purify only dividend income in proportion to the company's percentage of non-compliant revenue.
Capital gains purification method: Purify a percentage of capital gains when you sell shares.
AAOIFI purification method: Purify the exact amount of non-compliant revenue attributable to each of your shares annually.
The method you choose depends on your investment style and horizon. For specifics on calculations and a step-by-step guide to each method, refer to this detailed article on stock purification on our blog: How to Purify Stocks: A Step-by-Step Guide