Every scan runs across all 30 constituents of the Dow Jones Industrial Average using indicators recomputed after each close, with prices updating live during the session.
A screen across thousands of tickers returns names most people have never heard of. The Dow Jones is 30 large, heavily traded, widely held companies, so the same screen run over just those 30 produces a list that is short enough to act on and familiar enough to interpret. It is also the index most likely to already be in a reader's portfolio, directly or through a fund.
Because the Dow Jones is price-weighted, a scan hit does not affect the index evenly: a high-priced constituent breaking down drags the average far harder than a cheaper one. The companies page shows each stock's weight, which is worth reading alongside any of these lists.