For a moment, forget the stock market triggers. If you are a retail investor trading in stocks, a few basic principles of playing the market can help you build a robust stock portfolio and hold you in good stead through the ups and downs of the Street. Here are they:-

Diversify across businesses
Buying stocks in only one or two companies can be a very risky bet. A concentrated portfolio is like putting all your eggs in one basket. Similarly, too many stocks in a portfolio may become unmanagable. An ideal stock portfolio should have not more than 20-25 names across different businesses for diversification.

Be a regular investor
Stock investing doesn't mean having just ten shares of one company and twenty in another. Invest regularly to create wealth. Good stockpicking is all about knowing how to allocate your capital efficiently across the best ideas in a diverse portfolio.

Review portfolio frequently
While one investment strategy is to buy and hold, that does not imply that you put in your money and sleep over it. Market prices move, sometimes dramatically and you may end up having too much or too little exposure to a sector or stock. Review your exposure regularly.

Create your own rules
Formulate your own rules on when to buy or sell a stock based on an investment philosophy. Don't just follow the herd or come under peer pressure. What is good for others may not be suitable for you or your portfolio because your risk, investment criteria and entry price may be different.

Don't time the market
It's a very bad idea to wait for a stock or the market to reach a particular level to buy. Do set a price target for your preferred stock and let your own investment philosophy guide you whether you will buy a stock, take the money off the table or stay invested.

Sell at the right time
Stock investment is not about knee-jerk response to a market trigger. Do respond to triggers, but after you are convinced about their implications. Also, if a stock is a constant underperformer, and if you realise you made a poor decision, sell it. Don't wait for it to go up

Keep some cash in hand
Professional investors recognise that good investment opportunities come unannounced. Make sure you keep some cash available in your portfolio to pounce on these ideas. If you are fully invested, you might miss good opportunities due to lack of liquidity.

Be in a stock for the long haul
If a stock you own suffers a loss in any year it does not mean the company is doomed forever. If you believe in the core story of that company, you should stick it out for at least 10 years, if not 20 years.