Editorial: Special Issue for the 11th World Congress of the Bachelier Finance Society.

This article is an editorial for a special issue of Mathematical Finance dedicated to the 11th World Congress of the Bachelier Finance Society. The Congress, originally planned to be held at the Chinese University of Hong Kong, had to be moved to a remote island due to unrest in Hong Kong and later transitioned to an online format due to the COVID-19 pandemic. The article acknowledges the loss of key organizers and prominent figures in the field of mathematical finance during the three-year period leading up to the Congress. Despite the challenges, the article highlights the resilience of the community and the opportunity for international academic exchanges. The special issue contains papers presented at the Congress, which have undergone a rigorous reviewing process. The authors express gratitude to the organizers, local universities, and individuals who supported the Congress. [Extracted from the article]