[miohtama]

Most of exchanges and brokers have a dialog window “Looks like unusual order with high price impact - do you really want to execute yes/no”

So definitely an UI issue.

[TacticalCoder]

A "fat finger" of only 10x is not that much of a fat finger and may not be detected for it's probably nothing out of the ordinary compared to the brokerage account's size. The fat finger in TFA, however, is a quite bigger fat finger: $444 bn instead of $58m.

That's 10 000x. That one is, indeed, a UI issue.

[miohtama]

Also on fat fingers everyone will find this hilarious

https://thedailywtf.com/articles/Special-Delivery

[gpderetta]

That's not just an UI issue, the backend system responsible of executing the order should have caught the out of limits order.

[thombat]

Except that apparently they had such warnings for individual trades, but the bundle was implemented as "for(trade in bundle) transact(trade)". Which design has a certain appeal, standing on the shoulders of the peculiar handling of each trade, but with the terrible flaw that the bundle is never considered in its totality.