Market regulator Securities and Exchange Board of India (SEBI) has imposed a penalty of Rs1.9 crore on four former key officials of Karvy Stock Broking Ltd (KSBL) for several violations, including non-segregation of clients' funds and securities, misappropriation of clients' securities and diverting proceeds to group companies and illegally pledging credit clients' securities with banks and non-banking finance companies (NBFCs).