The article focuses on studying the theoretical framework of the connectedness between many stock markets and the Bitcoin market with a specific review in Vietnamese market. With a desk-based approach, content aspects are focused on including a research overview of financial contagion and inter-market relationship. The majority of the related researches confirmed that the contagion between Bitcoin and stock market existed in many different contexts. The two most popular mechanisms for the spillover effect analyzed in these studies were safe-haven characteristic and investor behavior. If Bitcoin could serve as a safe – haven, investors tended to shift the portfolio from stock to this crypto in case of a downtrend leading to the movement of cash flow out of stock market. On the other hand, when investors had sentiment on Bitcoin value, they would prefer investing more in this crypto to holding only securities, which also results in a contagion between two markets