Signing a contract might not solve everything if the BTC price drops. Remember, this is Bitcoin we're talking about - it's really unpredictable.
Even with a contract, your siblings might still be upset if they lose money. Are you ready to take that risk with your family ties? It's not just about the money; it's about keeping a good relationship with your bros and sis. Maybe think about a safer investment or get a financial advisor on board to guide you all.