As a result of globalization, the removal of barriers to international capital has created a source for countries in need of capital. These capital sources referred to as short-term capital movements or simply portfolio investments, provide significant benefits to the economy when they first enter the country. Investment instruments are instruments used by those who have excess capital in their hands in order to make a profit. The aim of this study is to reveal the cointegration relationships between portfolio investments and investment instruments in Türkiye. The motivation for this study is that there are few studies in the literature that examine cointegration relationships between all investment instruments and portfolio investments. The study comprises quarterly data covering the period from 2009Q1 to 2023Q2. The data has been obtained from the CBRT EVDS system. According to the results of ARDL cointegration analysis; there is a cointegration relationship between the variables both in the short and long run. According to these results, in Türkiye, investment instruments do not significantly affect portfolio investments, but portfolio investments significantly affect investment instruments.