What Happens to the Theta of a Deep OTM Option near Expiration?

The Theta of a deep out-of-the-money (OTM) option approaches zero as expiration nears. This is because the option has a very low probability of becoming profitable, and thus its remaining time value is minimal.

Since Theta measures the daily decay of time value, a minimal time value results in a minimal Theta. The option effectively becomes worthless due to the lack of time and intrinsic value.