Speculation: engagement in business transactions involving considerable risk but offering the chance of large gains, esp. trading in commodities, stocks, etc., in the hope of profit from changes in the market price.
How many variables effect the price of a stock? Management? Economies? Product competitiveness? Competition? Patents? International factors? Distribution channels? Product life? Efficiencies?
Honestly, wouldn't you have to be brilliant just to be able to identify all the variables, not to mention assess each one and how they relate to one another?
Investment: he investing of money or capital in order to gain profitable returns, as interest, income, or appreciation in value. A devoting, using, or giving of time, talent, emotional energy, etc., as for a purpose or to achieve something.
When a business owner invests in a piece of equipment, they have the benefit of a) huge expertise in their venture, b) all the incentives to make it work, c) skin in the game. Although there is certainly a element of risk, the number of variables are far "tighter" than that of a speculation.
My investment strategy is not to speculate. Rather, it is to invest giving the right individual (i.e. someone who has a tried and proven track record) the right incentives (i.e. profits subject to me making my money first).