In this context, 'valoriser' is almost certain to mean "to value, assign a value to" -- to the dismay of many francophones who feel this verb ought NOT to be used with this meaning (but instead reserved for 'enhance/upgrade' etc.).

Of course, no one would say it like this as a subject heading, so you need to tell us more of the context. How is the valuation done, and who does it? What about positions that have not been/cannot be valued?