Dow Jones Reprints: This copy is for your personal, non-commerical use only. To order presentation-ready copies for distribution to your colleagues, clients or customers, use the Order Reprints tool on any article or visit www.djreprints.com

By JIM MCTAGUE | MORE ARTICLES BY AUTHOR

ERIC SCOTT HUNSADER, a self-taught programmer who became an expert on market data, argues that rogue traders using high-speed computers deliberately slow the stock market's consolidated tape every trading day, to create fleeting price mismatches among the dozen exchanges handling NYSE-listed shares and to profit from the momentary differences.

Hunsader has given federal regulators an intriguing analysis that suggests that such market manipulation...