KARACHI- Karachi stock prices crashed over four percent today as selling was seen by investors worried over political uncertainty in the country. “There is heavy selling on concerns over political situation. There is a lot of uncertainty,” said a senior dealer. Dealers said the negative political developments will continue to weigh on the market in days to come. Anti-government protests by Pakistan Tehreek-e-Insaf and Pakistan Awami Tehreek are having a negative impact on the market. According to the dealers, the market had shown some phenomenal gains in the last few months.