Big Board Effects New Day Trader Rules

New rules increasing the minimum balance “day traders” must have in their accounts to start a certain type of risky trading took effect at the New York Stock Exchange on Monday.

The rules require that a day trader deposit $25,000 in an account before being allowed to start margin trading on stocks. The previous minimum for trading on margin, which involves using a brokerage house’s credit to buy or sell stocks, was $2,000.

The regulations should have little effect on professional day traders, said Craig Schlifstein, founder of day-trading brokerage Blackwood Trading. Blackwood requires its traders to maintain a minimum account balance of $50,000.

But brokerages that try to lure smaller online traders with low minimum account balances will suffer, Schlifstein said. Many brokerages, such as Charles Schwab Corp. and TD Waterhouse Group, already have been hurting as small investors cut back their trading activities.