Many accepted financial rules are not timeless. Stocks only began consistently outperforming bonds after WWII, and inflation-adjusted US home prices were flat for a century before 1997. This reveals that much financial advice is based on recent history, not immutable laws, making it a poor guide for the future.

Historical data shows no exceptions to the rule that an asset class reaching a two-standard-deviation (two sigma) valuation above its long-term trend will eventually return to that trend. This statistical certainty applies to stocks, bonds, commodities, and currencies, making severe drawdowns from such peaks inevitable.

The tendency to invest heavily in one's own country, known as home country bias, is a widespread and historically costly mistake. Global diversification typically provides lower risk and smaller drawdowns while still capturing market growth, as the next big winner is unpredictable.

The modern mantra of "stocks for the long run" is a historical anomaly. For most of U.S. history, including the entire 19th century and up until WWII, bonds were the superior or equivalent long-term investment compared to stocks.

The S&P 500's high concentration in 10 stocks is historically rare, seen only during the 'Nifty Fifty' and dot-com bubbles. In both prior cases, investors who bought at the peak waited 15 years to break even, highlighting the significant 'dead capital' risk in today's market.

Even in severe depressions or hyperinflations, stock markets eventually recover because they represent real assets. The only historical cases of complete and permanent investor wipeouts, like in Russia post-1917 and China post-1949, occurred when a new government regime forcibly shut down the markets entirely.

An investor's lived experience can be a poor guide to long-term market realities. For example, someone who started their career after 2009 has only known a US stock market that consistently rewards dip-buying, a pattern not representative of broader history.

Historical data across global stock markets shows that after a market doubles in one year, it is just as likely to double again the next year as it is to give back its gains. A full crash wiping out all profits is an extremely rare, sub-1% probability event.

Despite popular narratives about the rise of emerging markets, historical data shows that the "Anglo countries" (U.S., U.K., Canada, Australia, New Zealand) have persistently dominated global market cap. This challenges the assumption that developed markets are in terminal decline relative to emerging economies.