Good points. The decline we should be worried about is not in the currency, but in the competitive advantage of the US relative to other countries. If it gets

Good points. The decline we should be worried about is not in the currency, but in the competitive advantage of the US relative to other countries. If it gets more affordable to do business elsewhere, you'll find fewer and fewer good companies on US financial markets. (Many claim SarbOx has already done significant damage here.) If emerging economies can continue to reduce costs -- by tackling security problems, corruption, red tape, improving education and infrastructure, etc. -- faster than we can, US equities may lose their world-leading position. That's not to say it's a zero-sum game; it's quite possible that all the world's equities markets could do well, and the US could lead without being dominant. But equity investments are more strongly tied to their country of origin than globally traded "real" commodities like timber or oil, so if you think the US might lose some competitive advantage -- like if it got significantly less appealing for valuable workers to immigrate here -- you might want to skip the stock certificates and instead buy the paper they're printed on.