How Does Delta Affect the Theta of an Option?

Delta and Theta are related, particularly through the concept of moneyness. Options with a Delta near 0.5 (ATM) have the highest absolute Theta.

As Delta moves towards 1 (deep ITM) or 0 (deep OTM), the absolute Theta decreases. This is because high Delta options are mostly intrinsic value, and low Delta options have little time value left, whereas ATM options are pure time value.