Everyone posting so far has missed the easiest point with options. While you have a non-zero risk of getting assigned at any time when you are writing options the probability of this occurring is realistically near 0 in most cases. The cases it is not: 1. Violent moves in the underlying causing people to exercise the options you have written defensively at a massive loss (this is ok for you). 2. A dividend is approaching. (2) is the most likely case of getting exercised early especially on large stocks. Don't hold short positions through ex-dividend. If the losses experienced exercising at a small loss are outpaced by the gains in dividend, it makes game theoretic sense to exercise.