69It is settled case-law that only a ‘legitimate’ expectation can be protected. Specifically, the expectation is protected only where the person concerned could reasonably count on the continuation or the stability of the situation created (Opinion of Advocate General Bot in Commission v Koninklijke FrieslandCampina, C‑519/07 P, EU:C:2009:256, point 78). The benchmark for the EU Courts’ assessment of whether the alleged expectation is legitimate is a reasonably prudent, discriminating and diligent trader (see judgment of 16 October 2014, Alcoa Trasformazioni v Commission, T‑177/10, EU:T:2014:897, paragraphs 60 and 72 and the case-law cited). They also take account of the area or subject matter covered by the alleged legitimate expectation. Thus, in view of the objective nature of the concept of State aid (judgment of 16 May 2000, France v Ladbroke Racing and Commission, C‑83/98 P, EU:C:2000:248, paragraph 25), the Commission’s assessment that a certain measure does not constitute State aid does not create a legal situation which may be regularly altered by the institutions in the exercise of their discretionary power, as may be the case particularly in an area such as that of the common organisation of the markets, the objective of which involves constant adjustment to reflect changes in economic circumstances (Opinion of Advocate General Léger in joined cases Belgium and Forum 187 v Commission, C‑182/03 and C‑217/03, EU:C:2006:89, point 419), so that traders cannot be justified in entertaining an expectation that an existing situation will be maintained (see judgment of 15 July 2004, Di Lenardo and Dilexport, C‑37/02 and C‑38/02, EU:C:2004:443, paragraph 70 and the case-law cited)