Ditto to Aries411's post
It's all about time frame and the type of investments
Putting money in a mix of blue chip stocks and bonds each paycheck for the long-term is certainly not gambling. First, putting in a bit at a time instead of a lump-sum reduces the risk because you are buying shares at different prices over time. Second, yes, even blue-chip stocks can have a terrible year or two, but you only lose if you sell. If you just stay put, history is on your side and you will almost certainly experience a rebound.
Short-term trading in stocks or derivatives is
gambling .....and I believe one of the U.S. Democratic Presidential candidates proposed putting an extra tax on these types of transactions. I also consider buying on margin to be gambling (buying a position in something with borrowed funds)
It's an interesting topic, but as long as you are well-diversified, hold for the long-term, and don't try to time the market, one should average 3-6% growth over time. Yes, it's boring, but this is why it's not gambling