> A slight over simplification, for example s&p was negative 1% per year from Jan 2000 to Dec 2009. Plus the cost of your leverage.
For the 2000s, a US-only investor would only have been saved from the S&P500 by having at least 20% bonds and rebalancing:
* https://www.forbes.com/sites/advisor/2010/09/13/its-not-real...
Of course if you were not US-only, but rather internationally diversified (and rebalanced), you would also have been fine. Diversification is important, even for Americans (cited sources in the description):