SEC is approaching rules that could change how the exchange works

WASHINGTON — The Securities and Exchange Commission is preparing to propose major changes to how the stock market invests later this fall.

Chairman Gary Gensler last year directed SEC officials to explore ways to make the stock market more efficient for retail investors and public companies. While aspects of the effort are in various stages of development, an idea has gained traction to require brokers to pass orders from most individual investors to auctions, where trading firms compete to fill them, people familiar with the matter said.