SEC looks into effects of high-frequency trading

The Securities and Exchange Commission is looking into how high-frequency trading, which some estimate accounts for 50% or more of all equity trading in the U.S., affects markets, sources said. As lawmakers are scrutinizing the trading practice and other market developments, the SEC is not expected to publish a discussion paper on the strategies until December at the earliest. A congressional committee will discuss high-frequency trading, dark pools and other developments on Wednesday.

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