In 2016 44% of foreign direct investment in the region was concentrated in Panama, and a fourth consecutive year of increases was recorded, with 16%, while Costa Rica received 27% and increased by only 1.1%.

From chapter I of the report “Flows of FDI in Latin America and the Caribbean”, by the ECLAC:

FDI into Central America grew by 3.7% in 2016 and totaled 11,833 million dollars .The increase in investments to the two main recipients of the subregion -Panama, which recieved 44%, and Costa Rica, 27%- compensated for the drop in FDI to the other Central American countries.

With growth of 15.9%, Panama received investments of US $5.209 billion in 2016, a record figure that was reached after four consecutive years of increases and which is part of an upward trajectory that began in the mid-2000s. With this value, the country ranked sixth in Latin America and the Caribbean, behind Peru.  The largest component of FDI that entered Panama was the reinvestment of profits (66% of the total) and the level remained at levels similar to those of 2015 (up 2%).  Loans between subsidiaries accounted for 19% of total FDI and fell by 7%, while capital inflows accounted for 15% and remained the smallest component of FDI as in the last four years.  

See report by the CEPAL “Foreign Direct Investment in Latin America and the Caribbean 2017” (In Spanish).