New Delhi, March 26 -- Retail investors may fear dipping their toes into a volatile market amid the global oil supply crisis, geopolitical tensions, war in West Asia and other uncertainties. Amid this, Berkshire Hathaway Founder-Chairman Warren Buffett's simple but key investment lessons can be good yardstick. 

The 'Oracle of Omaha' as he is known, is a big proponent of keeping things simple. For retail investors, who may lack technical and in-depth stock market background, Buffett suggests the 90/10 rule. 

According to the billionaire, average investors should divide your funds as follows: Put 90% into low-cost S&P 500 index fund (for India the Nifty 50, Nifty 500 and BSE 500 are equivalent alternatives), and the remaining 10...