[LeroyRaz]

Money Extraction: fighting over a slice of pie.

Wealth Creation: creating new pie.

In practice, a lot of things that look extractive (e.g., designing better high frequency trading algorithms) potentially have some marginal utility (e.g., creating market liquidity), but the money high performing people make is likely larger than the utility they add to the system (because most of the money in having the best high frequency trading algorithm comes from beating other people's high frequency trading algorithms).