Hacker Triggers Halt on Hong Kong Exchange (bloomberg.com)

Seem HK Exchange don't expect such DDoS for the simple document hosting platform.

Interesting is that all they did was take down the website where all company anouncements are made - a simple DDOS would do this. As a result, the exchange suspended the shares of companies that were due to release price-sensitive information. It is a huge impact for a relatively simple and low-tech attack.

This could be mitigated by placing all announcement docs on two large CDNs as a backup and switch over if the main system fails.