What should you do next? Review your email and account security.
Jagex recommend a three layer approach to account security: * 2-step verification protecting your email * Authenticator protecting your RS account * Bank PIN inside your account protecting your items and gp If you didn't have these, you need to set them up right away.
Yes, email email@example.com and report the hijack. Jagex will check the trade logs and track the hijacker and, depending what they find, will take action against them.
When I say "depending what they find", it's because the investigation of your account may turn out to be part of a much larger hijack investigation. Jagex may not take action straight away as they may still be gathering evidence.
It is important to report hijacks as Jagex don't necessarily know a hijack has occurred until it gets reported. Most hijack reports are logged as part of account recovery but, if you didn't need to 'recover' your account, then a report has not been done.
Jagex won't share with you the account names of the accounts that traded your items. Usually those accounts are not the hijackers main. Hijackers typically move items through a web of stolen accounts. Your account may have been used to process the stolen items from other accounts. Some of the accounts may be completely innocent, just purchasing an item without realising it was stolen.