Fritz Leutwiler's advice to investors centers around the concept of 'dry powder,' which refers to cash or liquid assets that can be quickly utilized when investment opportunities arise. He argues that maintaining liquidity is crucial, especially in volatile markets where corrections can present attractive entry points. Investors who keep cash reserves can act decisively during market dislocations, gaining a psychological advantage over those fully invested who may panic during downturns. However, Leutwiler warns against excessive cash holdings during bull markets, as this can lead to missed opportunities for gains. The appropriate level of dry powder varies based on an investor's risk tolerance and market conditions, with long-term investors typically holding 10-20% in liquid assets. Ultimately, Leutwiler's insights highlight that successful investing is not solely about asset selection but also about timing and adaptability in an uncertain financial landscape.