Every English word has at least one syllable where the stress falls. Occasionally the same word can vary its stress depending on its meaning:
They signed a contract.
She did not wish to contract measles.
The farm grew wonderful produce.
This contraption will produce a loud bang.
In practice, it is difficult for English speakers not to emphasise at least one of the syllables in a Greek word, but there is little agreement about how to do this. Some speakers place the stress where it seems most natural to them, others place it on the syllable containing the accent. You should be prepared to encounter both methods.