The most awkward flash-crash possible

When your stock exchange wipes 99.75 per cent off its own value in less than a second, it might be t

Felix Salmon shows us his chart of the day, from Zerohedge (click for big):

He explains:

What you’re seeing here is the price of shares in BATS, at 11:14 [Friday] morning [ET]. The white spots are trades: there are 176 of them altogether. They start just below the IPO price of $16, and then just fall lower and lower and lower until the stock is trading for mere pennies. But the key number you want to look at here is not on the y-axis. Instead, it’s the chart report at the very top:

Elapsed Time: 900 Milliseconds

BATS, which stands for Better Alternative Trading System (a name which will surely come to haunt them), is a stock exchange based in Kansas. While most American stocks are listed in one of the two big exchanges, NYSE or Nasdaq, there are multiple venues where stocks can be traded – around 50. These exchanges communicate with each other to work out a "national best bid/offer" (NBBO), which is kept consistent throughout the venues. At least, that's the plan.

What appears to have happened is that a "software bug" (BATS aren't particularly forthcoming with the details) severed, or otherwise corrupted, the link between BATS and the NBBO system for all stocks beginning with A or B. This combined with the high-frequency trading that operates heavily in BATS (indeed, which it was largely set-up to enable) to allow stocks to plummet in less than a second.

For the most part, no-one was hurt. The error was confined to the one exchange, which rolled back the transactions. We would have all learned a valuable lesson about the dangers of computer-aided trading, the proponents of a financial transactions tax would have another weapon in their armoury (high-frequency trading isn't financially viable with a financial transactions tax in place), and everything would go back to normal. We would have, were it not for an excruciating coincedence:

The share that is charted above is that of BATS itself - that is, the company running the stock exchange which suffered the glitch. Not only that, it is the value of BATS on the day it held its initial public offering. Awkward.

BATS the company was supposed to be the first one to be listed (as opposed to merely exchanged) on BATS the exchange. For a smallish company based in a suburb of Kansas City, that is quite a big power grab. Needless to say, it didn't go to plan. The IPO is now cancelled, and the company has "no plans" to try it again soon. Which is unsurprising.

London 2004, back when trades were done by people, not Skynet. Credit: Getty

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Photo: Getty
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Who will win in Manchester Gorton?

Will Labour lose in Manchester Gorton?

The death of Gerald Kaufman will trigger a by-election in his Manchester Gorton seat, which has been Labour-held since 1935.

Coming so soon after the disappointing results in Copeland – where the seat was lost to the Tories – and Stoke – where the party lost vote share – some overly excitable commentators are talking up the possibility of an upset in the Manchester seat.

But Gorton is very different to Stoke-on-Trent and to Copeland. The Labour lead is 56 points, compared to 16.5 points in Stoke-on-Trent and 6.5 points in Copeland. (As I’ve written before and will doubtless write again, it’s much more instructive to talk about vote share rather than vote numbers in British elections. Most of the country tends to vote in the same way even if they vote at different volumes.)

That 47 per cent of the seat's residents come from a non-white background and that the Labour party holds every council seat in the constituency only adds to the party's strong position here. 

But that doesn’t mean that there is no interest to be had in the contest at all. That the seat voted heavily to remain in the European Union – around 65 per cent according to Chris Hanretty’s estimates – will provide a glimmer of hope to the Liberal Democrats that they can finish a strong second, as they did consistently from 1992 to 2010, before slumping to fifth in 2015.

How they do in second place will inform how jittery Labour MPs with smaller majorities and a history of Liberal Democrat activity are about Labour’s embrace of Brexit.

They also have a narrow chance of becoming competitive should Labour’s selection turn acrimonious. The seat has been in special measures since 2004, which means the selection will be run by the party’s national executive committee, though several local candidates are tipped to run, with Afzal Khan,  a local MEP, and Julie Reid, a local councillor, both expected to run for the vacant seats.

It’s highly unlikely but if the selection occurs in a way that irritates the local party or provokes serious local in-fighting, you can just about see how the Liberal Democrats give everyone a surprise. But it’s about as likely as the United States men landing on Mars any time soon – plausible, but far-fetched. 

Stephen Bush is special correspondent at the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to British politics.