The ratio of the change in an options price to the decrease in its time to expiration. also called time decay.

A letter of the Greek alphabet corresponding to th in English; -- sometimes called the unlucky letter, from being used by the judges on their ballots in passing condemnation on a prisoner, it being the first letter of the Greek qa`natos, death.

The sensitivity of the value of an option with respect to the time remaining to expiration. It is the daily drop in dollar value of an option due to the effect of time alone. Theta is dollars lost per day, per contract. Negative Theta signifies a long option position (or a debit spread); positive Theta signifies a short option position (or a credit spread).

The measure of change in the value of an option relative to the continuous decrease in time to expiry.

that state of the mind we are in while dreaming

Brainwaves (4-7HZ) produced by the subconscious mind. Theta waves are present during dreaming and the REM (rapid eye movement) state. The theta state is also associated with memory, learning, and creativity. Theta waves are the key to opening the repository of our emotional "stuff." Theta is a deep hypnosis or meditative state.

A brain frequency that is between 4 and 8 c/s. Passive meditation occurs while the brain is in Theta. This is also the frequency of the brain a person is in during deep hypnosis. The mode of thinking is inductive.

a national history society

a professional society, the objective of which is the promotion of the study of history by the encouragement of research, good teaching, publication, and the exchange of learning and thought among historians

Thought, soul or spirit