Why does Bane's stock exchange robbery actually work to bankrupt Bruce Wayne?

Question

In the movie The Dark Knight Rises, Bane robs the Gotham City Stock Exchange, more specifically with the purpose of bankrupting Bruce Wayne.

What I don't understand and feels like a plot hole to me: Why does this transaction actually go through? Not only are there tons of witnesses that can attest that this transaction was essentially done fraudulently, one would expect that such a major stock exchange would just be emergency hard shutdown within seconds if a robbery attempt were to take place, just blocking all transactions until the danger has passed. The transaction done in the robbery to me just feels like in the real world, it would never have succeeded.

Why does this robbery manage to bankrupt Bruce Wayne like this?

Answer 1

You are actually completely right. This is plot hole, probably because of rushed writing.

In real life such a 'coup' would never have succeeded. Any and all transactions done in such a fraudulent way, would indeed be blocked or the ones that went through would be canceled afterwards. There are plenty of witnesses that can say that Bane =/= Bruce Wayne. This scene was counting on, that no one would know the slightest bit of how a stock exchange works... and that plan failed.

What's worse is that even the type of transaction performed was incorrect for the intended purpose. Bane purchased puts, a type of insurance against dropping prices that allows you to sell your shares at a certain price even if the market price is lower. Since Bane's attack on the stock exchange would certainly cause a serious drop in prices or even a market crash, these puts are suddenly worth a lot more, than if the market would have continued as usual. Wayne Enterprises would in such a case have lost a lot less than other companies.

Talk about a failure on all accounts.

Source: The Atlantic

Answer 2

Ignoring the practicality of whether those transactions would be caught or not, I think the idea is that transactions entered with legitimate authorization codes would not be able to be filtered out from the massive volumes of transactions happening every second. Basically, anyone losing money is going to claim that their claims were bogus ones, whether true or not.

By making a futures transaction (even if the wrong kind as claimed in another answer, I neither dispute nor agree with that), where one only needs a fraction of the money at stake to place the option, but then the reckoning must be settled at a later time, they are able to fraudulently put a large portion of his assets at risk, again, supposedly, without those transactions being able to be definitively identifiable as fake.

Yes, once the threat is identified, an exchange would be able to suspend transactions, but what they were really doing was not identified until much, much later, so that would not help here.