Seal coin into a purse.
What you seal is opaque to everyone. It sits on the floor until a drawer takes it, and every draw made in the meantime pays it carry. A fat purse is taken rarely and pays a great deal at once; a thin purse is taken often and pays little. Neither is worth more than the other.
Between 50 and 250,000.
What this purse implies
Type an amount to see its draw probability, the carry it expects, and how long it is likely to sit sealed.
Purse size is a variance choice, not an edge. Every open purse is paid an equal share of every draw price, whatever is inside it, so the expected return is identical at 50 and at 250,000: 4 percent of whatever you sealed, over the purse's life. Big is rare and brutal, small is frequent and mild. There is no size that beats another.
Sealing is final until the purse is drawn. There is no unseal and no secondary market. The coin leaves your balance now and returns only when somebody draws this purse — which may be within the hour or may be a very long time, and the fatter the purse the longer that wait is expected to be. Carry accrues while it waits and is paid to you with it. This is the sealer's real risk, and it is the whole of it.