Opportunity loss
From ACT Wiki
The worsening of a financial position when effectively 'locked in' to a course of action or to a particular fixed price or rate, compared with the alternative which could have been followed without the lock-in.
For example, there is always a risk of opportunity losses when we use a fixing instrument to effectively lock in a (committed) market price.
We are effectively locked in to the predetermined and committed market price, instead of being free to take advantage of actual market rates (if they turn out to be more favourable).
See also