CV = Grades, relevant exp (or non-rel), extra currics and other achievements.
when you write one, just ensure you place emphasis on the key competencies the company and department would want.
For IBD, social skills, academic skills, commitment, attention to detail, responsibility, communication skills etc..
MC pretty much the sae but dependent on firms you're applying to, you want brand names on the CV whether that be through experience from strong companis BB firms/Big4 w/e else or strong universities Oxbridge/LSE etc..
if you have numerical examples of how you've improved productivity/efficiency definately put that in the relavant plac eon CV. Ensure you have detail to back it up, if ever prompted