I’m 25 years old and have been working as a junior manager in a trading company for 4 years. Recently, our internal email said that another department is looking for a new boss. I sent my resume. But...

Shaming you for asking, if they did, would be wrong. However, with all due respect to your goals and achievements, I honestly believe, leadership of a... Dpt. usually requires life experience that most 25 y.o. people lack. Part of it has nothing to to do with performance! I am sure, you will agree in 5 years. I must add, I do not know your company, so there may be exceptions.
I think, nothing is wrong waiting a few years for a big leadership position. I personally may have difficulties with a very young superior - I experienced one young superior having no understanding for my physical/health issues in a meeting, and shaming me for it.
I am also asking myself if some of the people whose most important career goal is to climb the ladder are the best choice for leadership positions. Would they care about things like the well being of colleagues, a good work environment, ie. the flourishing of our company *long term* - ie., not only numbers for next quarter for which we get bonusses? more