To let the cat out of the bag, the biggest drop in Dow Jones took place on Black Monday in October 1987 and it might sound jaw dropping that day 24% drop occurred in Dow Jones which is the largest single-day decline in the history of the Dow Jones.
$500 billion got vaporised in the U.S. stock markets alone. And the contagion was truly global, crushing stock markets in Australia, Hong Kong and the UK.
Thus the best bet to beat such type of scenario is to use the delivery stock tips and get out by booking profit in a short period after breakout. You can see biggest fall in Indian stock market here.