theta

Theta represents time decay—the option loses value every day even if the underlying price doesn't move.Theta 代表时间衰减——即使标的资产价格没有变动，期权的价值每天都在减少。

Options sellers benefit from theta decay, earning premium income that erodes the value of long option positions over time.期权卖方受益于 Theta 衰减，通过赚取权利金收益，随着时间推移侵蚀了多头期权头寸的价值。