REST API issue history sorting order

Hi,

I am currently building a system using the REST API which analyses the issue history as part of a function. For this specific function it is necessary to get the issue history in either ascending or descending order (by updated date/time). Is it always guaranteed that the results from the REST request come back with the newest entry first?
It is certainly possible to sort the list but that would cost a lot of computing time which would be unnecessary if I could rely on pre sorted results.

Thanks,

Jan