> SoftBank was up 22% within a couple days

Softbank's rally began in Japanese markets on 3 September and American markets on 4 September. OpenAI announced on 8 September. When OpenAI delayed its IPO plans on 13 September, Softbank sank back to its 7 September level [1].

[1] https://asia.nikkei.com/business/markets/softbank-group-plun...