1. Buying a position means that investors build long positions in the market, that is, they expect prices to rise and hope to make profits from it.

2. Second, in futures trading, when the price rises to a certain extent, investors choose to sell some positions in time, which can lock in some profits and reduce the risk of holding positions.

3. The third stop loss line is the set price. When the futures price reaches this level, investors will automatically close their positions to limit further losses.