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Traders work on the floor of the New York Stock Exchange at the end of the trading day on Oct. 4, 2011 in New York City. - 

Steve Chiotakis: Big bank Morgan Stanley swung to a profit
in its last quarter thanks to some accounting moves there. But Goldman Sachs and other Wall Street banks said this week their numbers weren't as good because of big volatility in the stock market. For retail brokerage firms, volatility isn't so bad. Companies such as E*Trade -- which also reports today -- have been doing quite well.

Marketplace Senior business correspondent Bob Moon reports on how day traders are doing.

Bob Moon: A lot of traders were clicking away on the websites of retail brokerages this summer for a variety of reasons. Many were simply trying to get their investments out of harm's way. But some analysts also credit a surge in traders looking to make a quick buck on the day-to-day swings.

Michael Wong: Volatility is one of the best friends of day traders. The more volatility you have in the market, the more opportunities there are for day traders to potentially make money or lose money.

Morningstar analyst Michael Wong notes that TD Ameritrade reported some of the busiest trading days in its history during this summer's market turmoil. Likewise, Schwab.

It's not just volatility that's luring day traders back to the stock market. Wong says retail brokerages are offering customers increasingly sophisticated software.

Wong: It's almost leveling the playing field, and giving some of the retail investors some of the tools that formerly were reserved only for institutional brokerages and hedge funds.

Surprise: The big guys aren't the only ones using powerful algorithms to suck money out of the market.

I'm Bob Moon for Marketplace.