Long long ago. So long ago that one might call it a different life.
Index yes. Stock yes. Bonds yes. Derivatives no.
Exactly how long ago?
Well, i recall how folks around me were telling me that this newcomer Zerodha with its “zero brokerage” was surely a scam. 
Though no-one knew exactly what the “scam” was!
However, subsequently, after discovering sovereign bonds on the secondary market offering assured predictable exits (both value and date), known while buying a bond itself, and achieving 10-12% annualized returns over various years since then, my risk/reward appetite continues to be satisfied, without having to dip into riskier approaches.
As with everything, there’s probably a chance the niche i’m currently in, goes away. But, at this point i doubt it is going away anytime soon, as the last 5 years of telling everyone about it who is wiling to listen, at every single opportunity i get (online and offline) , has made no significant difference to the market. Apparently, no one else is interested. 
However, on the off-chance that the niche vanishes someday, feels good to know TradingQnA has been a great source of what else works and what doesn’t.