It's zero-sum over the short term, but not over the long term -- "beating the index" is (kinda sorta) another way of saying "dragging the index towards efficien

It's zero-sum over the short term, but not over the long term -- "beating the index" is (kinda sorta) another way of saying "dragging the index towards efficiency." It means investing in stocks that are going to perform, which (kinda sorta) like investing in companies that will be successful, which increases the size of the pie. Of course, with the amount of money the OP is likely to be investing, it's completely sensible to ignore market impact.