Stock exchange indices provide a general view on the performance and outlook of financial markets. This paper presents a comparative empirical study on the performance of BET Index and ETF Patria TradeVille, the objective of our analysis is to test the qualities of the ETF that tracks the composition and performance of the BET index, by examining the long-term relationship between the price of the TVBETETF on BSE and the underlying BET index, determining whether there is a semi-figurative link between the two, according to the ASF regulations for trading as an Exchange-traded-fund on BVB.