The insight:
Here's an analysis of 9 years of data of Nifty50, showing that Nifty50 gave a weekly gain >3.5% 19 times (i.e in 19 individual weeks). This is roughly 2 times a year, or 4% of times.
Ideas to apply the insight:
Credit spread, Iron Condor, etcetera etcetera. It helps to know what is the "maximum likely movement" that Nifty50 will give on a weekly...