ALEX BRUMMER: FCA ripples its muscles over insider trading

Insider trading is one of the Citys oldest crimes. Barely a takeover happens without a run-up in the target company share price beforehand.

Advisers seek to prevent leaks by the use of code names and meetings in secret locations but it is impossible to plug all the gaps.

In recent times, the ritual of capital markets days has developed and key information is shared with big battalion investors and analysts.

This potentially gives financial professionals a head-start on private investors. Technology means that with the exception of deliberate deception, such as using burner phones, financial insiders are only too aware of how compliance officers and regulators are able to access communications traffic.

The delete button can be hit but the trace is still there on the hard drive or in the cloud.

It is comparatively rare that staff at a major financial firm find themselves before the beak on hard-to-prove insider charges.

The Financial Conduct Authority (FCA) is often given a hard time about the sclerotic approach to justice. The failure to produce a timely report on the implosion of Neil Woodfords fund management empire comes to mind.