Ordinary banks with precious metals in their accounts can do it. Buying up and killing down or using t+d as leverage is to collect part of the handling fee, which is quite easy to operate.
What I want to say here is that precious metals investment is fine, but we should be alert to the trap of the black platform. At present, most precious metal spot trading platforms are informal, so attention should be paid to screening. There are many black platforms in the precious metals market. Black platform trading is basically impossible to make money and easy to be quilted. There are many formal platforms, just like stock funds, which can have good returns if they operate well.