NEW YORK (MarketWatch) — Another finance professional who’s gone rogue. Sorry, Wall Street, but this sounds like a pattern.

The U.K’s Financial Services Authority on Tuesday said it fined Ravi Sinha, the former chief executive of JC FLowers’ U.K. division $4.51 million for charges related to fraud. Read full story on FSA’s announcement.

The fine comes on the heels of a similar FSA action alleging insider trading against David Einhorn and his hedge fund, Greenlight Capital.

It also comes amid the backdrop of Kweku Adoboli, a trader formerly with UBS AG UBS, -0.54% pleading not guilty to losing $2.2 billion by making unauthorized trades.

Like Adoboli proclaiming his innocence, Einhorn, Greenlight, Sinha and J.C. Flowers all deny the charges. And as UBS did, all of the firms argue that if there was any wrongdoing — and they are steadfast there wasn’t — all of the participants were acting alone, hiding their moves.

Profits tumble at Banco Santander

Essentially, they were cowboys.

OK. The financial industry employs millions across the globe. Maybe we’re just seeing a perfect storm of bad apples falling from the money tree.

Or, maybe Wall Street has a culture problem where blurring the lines between productive trading and law-breaking is standard operating procedure. I offer the joke, what do you call a rogue trader who makes money for his firm?

A managing director.

Surely the majority of bankers and traders out there play by the rules. But that doesn’t mean a cowboy culture isn’t pervasive or that supervision is either too incompetent or indifferent to curtail activity. And why should they? Supervisors never get called out in these cases.

Unless, like Sanha and Einhorn, the cowboy is running the whole company.

— David Weidner