Arbitrage
Etymology
From the French arbitrage, "arbitration" or "judgment," rooted in Latin arbiter, "judge" — originally the act of judging the best market among several. It entered finance in the nineteenth century to describe reconciling price differences across exchanges. Today it stretches far beyond trading, into phrases like "regulatory arbitrage" and "cultural arbitrage," where someone profits from a gap between two systems rather than two prices.
noun · /AR-bih-trahzh/
The practice of profiting from a price difference for the same thing across two markets by buying low in one and selling high in the other.
What it names
The engine that quietly enforces consistency in the world — every gap someone can exploit tends to close as they exploit it — and it generalizes to any mismatch you can stand between, from currencies to regulations to cultural taste.
Example
His whole business is regulatory arbitrage — incorporating in whichever jurisdiction taxes his kind of income the least.
Related idea
True arbitrage is riskless because the trades are locked in simultaneously; speculation takes on real risk by betting that a price will move in a direction over time.