Getting 2 columns from sets of 2 rows in Postgresql
You can use a self-join for that:

select ni.date,
       ni.stock_id,
       ni.report_value as net_income, 
       nr.report_value as total_revenue
from report_items ni
  join report_items nr 
    on ni.stock_id = nr.stock_id 
   and ni."date" = nr."date" 
   and nr.report_item = 'totalRevenue'
where ni.report_item = 'netIncome'
order by date desc limit 100