It's Blitz 1: All-Nighter for London Traders June 23

You can bet no one will be snoozing in the City of London come the evening of June 23.

What's probably a bigger political risk event than the 2008 global financial crisis, Greece exiting the euro, or Scottish independence for the UK? Unless you've been hiding in a cave somewhere, it's the upcoming June 23 referendum when voters decide whether to remain in the EU or leave it. Needless to say, I do not side with the xenophobic isolationists, but there are apparently several misguided souls who actually get to vote who do. While next to no sane business establishment supports the UK leaving the EU, its Prime Minister David Cameron nevertheless put the issue to a referendum for reasons I can hardly comprehend.

At any rate, there is an interesting Reuters story on how it will be all hands on deck in the trading rooms of British financial institutions the day, night, and early morning after the vote. Stay or leave, there will likely be large moves in equity, fixed income, foreign exchange markets. There is, in other words, plenty of money to be gained or lost. As such, it's going to be an all-nighter for any number of traders:

The world's biggest banks including Citi and Goldman Sachs will draft in senior traders to work through the night following Britain's referendum on EU membership, set to be among the most volatile 24 hours for markets in a quarter of a century.

A vote to leave the European Union on June 23 would spook investors by undermining post-World War Two attempts at European integration and placing a question mark over the future of the United Kingdom and its $2.9 trillion economy.

Citi, Deutsche Bank, JPMorgan, Goldman Sachs, HSBC, Barclays, Royal Bank of Scotland and Lloyds are among those banks planning to have senior staff and traders working or on call in London as results start to dribble in after polls close at 2100 GMT, according to the sources.

What sort of epoch-making moves might be in store if the anarchists get their way? Let us count the ways:

A vote to leave could unleash turmoil on foreign exchange, equity and bond markets, spoiling bets across asset classes and potentially testing the infrastructure of Western markets such as computer systems, stock exchanges and clearing houses.

Federal Reserve Chair Janet Yellen has cautioned that a Brexit vote could shake financial markets and potentially push back the timing of the next rise in U.S. interest rates.

Bank of England Governor Mark Carney has said sterling could depreciate, "perhaps sharply" and some major banks have forecast an unprecedented fall to parity with the euro and as low as $1.20 in the days following any vote to leave the bloc.

The Bank of England will be staffed overnight, with senior policymakers on call if markets go into meltdown. The finance ministry would not comment on its staffing plans.

Trading could get real exciting as you'd expect:

Officials and bank managers planning for the event draw comparisons with the 40 percent surge in the Swiss franc in January 2015, which bankrupted dozens of small investment funds and cost banks including Citi hundreds of millions of dollars.

Traders and analysts told Reuters they would expect a Brexit vote to cause sterling to 'gap', or plummet lower - as orders to sell the currency met an absence of willing buyers, leaving a blank spot on the price charts snaking across traders' screens.

Gaps can inflict huge losses on banks and traders, forcing them to bail out of trades at prices far below the automatic sell orders, or 'stops' they normally use to limit losses.

Currency market participants have urged the Bank of England to call on U.S. Federal Reserve if the turbulence gets really bad. The BoE could buy sterling with dollars borrowed directly from the U.S. central bank under arrangements first used in response to the global financial crisis in 2008.

Carney has said the Bank would not stand in the way of any exchange rate adjustment but would take the necessary steps to ensure markets remained orderly. It has not commented on whether or how the bank might intervene.

I remain incredulous that Prime Minister David Cameron has (1) allowed the UK and Europe's future to be so endangered to begin with by giving voice to these sorts of cheap pandering and (2) not really thought through what the consequences of a "leave" vote would be.

But that's just me. Come June 23, all traders will be at hand as belligerents strafe London once more. Unfortunately, the most regrettable thing is that they allowed all of this to be unleashed upon themselves rather than some foreign foe.