Buying up means doing more. Investors will earn spot silver at a low price when they see the market going up, and sell it at a high price when the market goes up.
Buy down, that is, short, investors see that the market will fall, they sell at a high price first, and then buy when the market falls.
The biggest advantage of two-way trading is that regardless of the bear market and bull market, investors can make a profit as long as they buy the right direction, which is equivalent to a 50% probability of making a profit.