Most people think Reduce-Only is simple. In fact, this is where mistakes are easy to make:
Reduce-Only orders can only reduce an existing position. They cannot increase a position or open a position in the opposite direction.
Many unexpected reverse positions happen because a position is closed twice: you close it manually first, then an earlier take-profit or stop-loss order triggers afterward, opening a new position in the opposite direction.
When placing exit orders or conditional orders in one-way mode, make it a habit to select Reduce-Only.
For comparison, the market quote is 74425.34 (24h -0.52%) for $BTC .