It's always a gamble particularly for those who don't know much about business and trends. One should be trying to discern new technologies and invest in them. I would be looking for those into de-salination of sea water and wind technologies as there are going to be severe fresh water problems in the near future and shortages of cheap energy. Those are not short term investments but should provide a really good return over the long run.
One should put most of their money in long term returns (so says Warren Buffet) but taking a long shot on short returns is fun so limiting ones' funds in those areas is usually safe.
I think a certain percentage of funds should be in real estate even if it means investing in a fund. Traditionally that provides the best return over a long haul.