Changes in Nasdaq Trading Due Today

The biggest change in the Nasdaq Stock Market’s 26-year history begins today as new trading rules go into effect that could eventually save investors millions of dollars. If the new Securities and Exchange Commission rules work as intended, customers can place stock orders that will compete with the buy and sell prices that professional traders post for Nasdaq stocks--potentially lowering trading costs. The rules are aimed at preventing a form of collusion among Nasdaq dealers, identified in Justice Department and SEC studies last year, in which dealers kept an artificially wide gap between buying and selling prices to fatten profits. The new rules could reduce traders’ profits by $3 billion this year, some industry analysts say.