It was mentioned when Mikel Arteta was paid 65 million to sign Kai Havertz last summer.
Havertz endured a difficult start but he settled in the team. So far he has made 37 appearances in all competitions scoring nine goals and providing three assists.
According to figures seen on the CIES Football Observatory Havertz is now worth 85 million up from 20 million.
For David Raya he is currently on loan from Brentford but Arsenal have a buy-out clause of 27 million.
According to CIES Raya is now valued at 34million more than Arsenal have agreed to pay him to Brentford.
Both players were misbehaved when they first started but they came up with the wrong criticism showing that Arteta was almost never wrong.