The article examines what factors affect the profitability of banks in Portugal from 2015 to 2018. They looked at things like how well the banks are managed, the quality of the loans they give out, how much money they have on hand, and how the economy is doing. They found that having enough money set aside (TIER 1) and giving out good loans (CVCT) make banks less profitable, while having enough cash on hand (RAL) makes them more profitable.