It's all Thatcher's fault

[Doggy Styles]

The very name, Big Bang, which she initiated in 1986 laid the foundations for the real explosion more than 20 years later.
All the hoi polloi whose only aim was to make a quick buck were allowed into the hallowed portals of the City, where for centuries, the upper class who (1) understood risk over the long term and (2) had the interests of the country (admittedly as a proxy for themselves) at heart, had run the roost with good sense and probity.
The result was to be expected.

HTH.

What you have said is like blaming the inventor of the motor car for today's drunken drivers.

Like it or loath it, the Big Bang was inevitable progress, and necessary for competition with foreign exchanges.

The failure was in regulating products and the balance sheets of investors funds, which became a problem when Brown shook up the regulatory system in 1997/1998.