So I work for company A who buys a lot of material from company B. We decided, as A company, to buy an increase of material from company B, company B is unaware of this as of today.

I want to invest like 8k in company B because I know company A is going to buy a lot from them over a long period of time (15 yrs at least).

Is there an ethical delimma here? Or am I over thinking this?