Diversification of assets while investing plays a vital role during investment. Predicting market movements is a difficult task as it depends on various factors. If you are a regular investor and looking for long term gains, then it is better to diversify you portfolio in such a way that you minimize your loss to a greater extent.
Don't over diversify
If you have lot of investments it does not mean that you should go for over diversification. Investments depends on the variety of the products not the quantity.
Buying too many mutual funds or stocks of the same sector may lead to duplication of holding, this may not help your investments.
Also, it is cumbersome to maintain a huge portfolio and keep track of various investments.
Right time to Exit
Buy and hold does not mean that, one should hold for life time. One should track the investments he has made any stock or MF is in junk status should be exited at right time. As holding them wont fetch you any gains.
While investing consider how much commission you are paying your firm. If commissions are higher than profits than better to look for another firms.
This is the most important part, because it all depends on how you allocate your assets depending on the risk and return you expect. Right mixture of all the assets are very necessary.
One can look for investing in other countries. You can do so through global mutual funds and exchange traded funds available in the market. Click to know things to keep in mind before investing in International Mutual Funds.