  We consider Geometric Mean Market Makers -- a special type of Decentralized
Exchange -- with two types of users: liquidity takers and arbitrageurs.
Liquidity takers trade at prices that can create arbitrage opportunities, while
arbitrageurs align the exchange's price with the external market price. We show
that in Geometric Mean Market Makers charging proportional transaction fees,
Impermanent Loss can be super-hedged by a model-free rebalancing strategy.
Moreover, we demonstrate that in such a DEX, the exchange rate is of finite
variation, so that loss-versus-rebalancing (the shortfall of providing
liquidity versus the corresponding constant-weights portfolio) vanishes.
