Except that I see no indication this is a Wall Street Journal article. The site is Ars Technica; the by-line says "By Felix Salmon (wired.com), Jon Stokes" and the end of the article says "Felix Salmon (felix@felix salmon.com) is a blogger for Reuters."
I think what @w1ntermute means is that we can expect Ars to screw-up finance stories just as the WSJ screws up tech stories. Kind of an admonition for when journalists choose to venture beyond their expertise.
That's odd; Felix Salmon writes almost exclusively for the financial industry, and used to run his own blog. Reuters hired him for his finance industry audience. It's surprising that he would make elementary errors regarding his industry of primary coverage.
It's easy to be wrong when it's so hard to make out what's right. Algorithmic traders are unusually secretive about their modes of operation. The primary knowledge dissemination mechanism is via employees moving.
