The fetch utilization indicates how large fraction of the data brought into the cache that is actually read before the line is evicted. The value is proportional to the bandwidth required for loads.

A low fetch utilization means that bandwidth is wasted by loading data that is never used. A large portion of the cache is also tied up storing data never being read. When optimizing software you should strive to maximize the fetch utilization.

Remember that not only explicit data loads cause a cache line to be fetched, stores normally cause a cache line fetch as well. It is therefore possible to get a 0% fetch utilization, which would indicate that a cache line is fetched but no part of the line is read before it is evicted from the cache.