Glossary
Index fund
A fund that simply holds every stock in a market index (e.g. S&P 500) in proportion, instead of trying to pick winners. Low cost and broad — the benchmark our study repeatedly failed to beat.
In plain terms
Because an index fund only rebalances when the index itself changes, its turnover, fees and realised taxes are all close to zero. The cheapest broad funds now charge a few hundredths of a percent per year — a cost bar active strategies must out-earn before they add anything.
In our tests the index is not a straw man: it is the thing that won. Fifteen-plus AI and systematic strategies were measured against a broad cap-weighted index, out-of-sample and after cost, and none beat it durably.
Related terms
Educational definitions only. Not investment advice.