Behavioral finance is an emerging field and limited work has been done in this field in the developing countries. This field of study comes into play when the traditional rational theories fail to explain the abnormalities in the market behavior. It incorporates human psychology and sociology to explain market anomalies. In this study, one specific market behavior, disposition effect, is analyzed, which is driven by human psychology. The disposition effect is the tendency of investors to sell winning stocks too early and holding losing stocks for toe long. As per the traditional market theory, a rational investor would sell off stock with falling prices to minimize portfolio losses. However, if intuitive thinking overpowers a rational decision-maker, the investor would want to keep holding on a losing stock in anticipation of the rising in price, thus aggregating portfolio losses. In addition to this, the relationship between the holding period and the illiquidity of the stock is analyzed. It is believed that stocks with greater illiquidity require higher transaction costs to be traded as the bid-ask spread is higher; therefore stocks with greater illiquidity should have longer holding periods. To empirically test these theories, data of the Pakistan Stock Exchange is taken from the fiscal year 2012 to 2017 for all non-financial firms. The variables included are holding period, annual return, illiquidity, market capitalization and volatility of each stock. The data type demands a static panel data analysis, where the unit of the cross-section is each firm and each year is the unit of time-series. The intercept model of the panel data analysis is used to analyze the data using both random effect and fixed-effect model. Pooled OLS regression is also done to get the best results out of all three models. According to literature, there is the problem of simultaneity between the holding period and illiquidity, which causes biased estimates of parameters due to endogeneity. To overcome the issue, a lagged illiquidity instrument is used in place of the endogenous variable. Thus, our estimation method is converted to two-stage least square estimation. The results validate the literature, by showing a positive relationship between the holding period and illiquidity. Furthermore, in the second series of regression, results show that Pakistani investors are rational decision-makers. However, after the sample is dissected, it is shown that investors, who invest in firms with greater trading activity and larger firm size, tend to exhibit disposition effect