I think a more effective definition involves socially productive activity. If support the creation of value to others in hopes of getting paid back over time th

I think a more effective definition involves socially productive activity. If support the creation of value to others in hopes of getting paid back over time through getting a fraction of the value created, that's investing. If I put money into something volatile in hope that I get more money out, that's gambling. Alternately, you could frame it in terms of positive sum vs zero/negative sum systems. The former is investing, the latter gambling.