A simple PostgreSQL solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\n-- Write your PostgreSQL query statement below\nselect \n       stock_name,  \n       sum(case when operation = \'Sell\' then price else NULL end )- sum(case when operation = \'Buy\' then price else NULL end) as capital_gain_loss\n       from Stocks \n       group by stock_name ; \n```
['PostgreSQL']