Bachelier Finance Society

https://www.bachelierfinance.org/

Quantnet

https://quantnet.com/forum/home/

International Mathematical Contest in Modeling (MCM/ICM)

https://www.comap.com/undergraduate/contests/

China Society for Industrial and Applied Mathematics

https://csiam.org.cn/

National Mathematical Contest in Modeling (CUMCM)

http://www.mcm.edu.cn/