Impact of Extreme Situations such as WW2 on “legendary” Investors' Returns?
"Possibly the best answer to why America became globally dominant after WW2 was written by a FRENCHMAN, Jean-Jacque Sergen-Schreiber, Le Defi American (The American Challenge). Probably the only legendary investor of the proper age to benefit from WW2 was John Templeton, who borrowed $10,000 before the war, and ended up with $40,000 afterward (both worth about ten times more in today's money). His story, and that of others, can be found in John Train's, ""The Money Masters."""
"In the words of David Einhorn, Flash Boys was ""based on a true story."" The way Lewis tells the story is extremely misleading, and you seem to have been suckered in.   HFT has reduced spreads to a small fraction of what they were 20 years ago, they are awesome for average people, who are retail traders. Lewis uses ""ordinary investors"" to mean guys like Einhorn, who do suffer from HFT because they make it hard to buy large blocks of stock without moving the price. But it is not a God-given right to buy stock without moving the price against yourself, and guys like Einhorn now understand how to trade given the current market structure." The short answer is if you own a representative index of global bonds (say AGG) and global stocks (say ACWI) the bonds will generally only suffer minimally in even the medium large market crashes you describe.  However, there are some caveats. Not all bonds will tend to react the same way.  Bonds that are considered higher-yield (say BBB rated and below) tend to drop significantly in stock market crashes though not as much as stock markets themselves.  Emerging market bonds can drop even more as weaker foreign currencies can drop in global crashes as well. Also, if a local market crash is caused by rampant inflation as in the US during the 70s-80s, bonds can crash at the same time as markets.  There hasn't been a global crash caused by inflation after countries left the gold standard, but that doesn't mean it can't happen. Still, I don't mean to scare you away from adding bond exposure to a stock portfolio as bonds tend to have low correlations with stocks and significant returns.  Just be aware that these correlations can change over time (sometimes quickly) and depend on which stocks/bonds you invest in. While JB King says some useful things, I think there is another fundamental reason why stock markets go down after disasters, either natural or man-made.  There is a real impact on the markets - in the case of something like 9/11 due to closed airport, higher security costs, closer inspections on trade goods, tighter restrictions on visas, real payments for the rebuilding of destroyed buildings and insurance payouts for killed people, and eventually the cost of a war. But almost as important is the uncertainty and risk. Nobody knew what was going to happen in the days and weeks after an attack like that. Is there going to be another one a week later, or every week for the next year? Will air travel become essentially impractical? Will international trade be severely restricted? All those would have a huge, massive effect on the economy. You may argue that those things are very unlikely, even after something like 9/11. But even a small increase in the likelihood of a catastrophic economic crash is enough to start people selling. There is another thing that drives the market down. Even if most people are sure that there won't be a catastrophic economic crash, they know that other people think there might be and so will sell. That will drive the market down. If they know the market is going down, then sensible traders will start to sell, even if they think there is zero risk of a crash. This makes the effect worse. Eventually prices will drop so far that the people who don't think there is a crash will start to buy, so they can make a profit on the recovery. But that usually doesn't happen until there has been a substantial drop. "You could use any of various financial APIs (e.g., Yahoo finance) to get prices of some reference stock and bond index funds.  That would be a reasonable approximation to market performance over a given time span. As for inflation data, just googling ""monthly inflation data"" gave me two pages with numbers that seem to agree and go back to 1914.  If you want to double-check their numbers you could go to the source at the BLS. As for whether any existing analysis exists, I'm not sure exactly what you mean.  I don't think you need to do much analysis to show that stock returns are different over different time periods." Many people think money velocity is the most important thing in the economy that is why war is *good* for the economy.  But during WWII the USA and all others countries had rationing.  The whole reason to have a better economy is so we can live better lives; not to put rationed on but we can buy.  After WWII where peoples lives better?  No we(US) had 418,500 dead, many wounded and many years of rationing.  Same apples to Hurricane Harvey families had homes and jobs.  Now they have nothing.  Just because they are spending retirement fund on rebuilding doesn't mean their lives are better.    So yes there is more velocity in money in where Hurricane Harvey hit.  But it is happening for the wrong reasons. From Dimson, Elroy, Paul Marsh, and Mike Staunton. Triumph of the Optimists: 101 Years of Global Investment Returns. Princeton, N.J: Princeton University Press, 2002: Disappointingly, the small firm effect has not proved the road to   great riches since soon after its discovery, the US size premium went   into reverse. This was repeated in the United Kingdom and virtually   all other markets around the world. Despite their disappointing performance in recent years, the very   long-run record of small-caps remains one of outperformance in both   the United States and the United Kingdom. Furthermore, mid- and   small-size companies are still an important asset class. Their   differential performance over long periods of history shows that there   is useful scope for investors to reduce risk by diversifying across   the “large” and the “small” capitalization sectors of the market.   Furthermore, given the pervasiveness of the size effect across the   entire size spectrum, it is important to all investors since the   size tilt of any portfolio will strongly influence its short- and   long-run performance. This holds true whether there is a size premium   or a size discount. The size effect has certainly proved persistent   and robust. What is at issue is whether we should continue to expect a   size premium over the longer haul. And accompanying charts:    And one chart from BlackRock: On Black Friday, 1929,the market fell from over 350 to just above 200. If you were following your plan then you would buy in at about 200. But look what the market did for two years after Black Friday.   It went down to about 50. You would have lost around 75% of your capital. I would say the most challenging fact for this assertion is that HFT firms operate with extremely limited capital bases. For a stock with say 10m shares ADV, even a very large and successful HFT strategy might use a position limit of no more than 5000 shares.  That is to say if you sum up and net the buys and sells for a stock across the day the HFT firm will never exceed 10,000 shares (2x position limits assuming it completely flipped) on a stock that trades 10,000,000 shares on a given day. The high volumes are attained through high turnover, the strategy might trade up to 500,000 shares (or 5% of the volume) attaining a 50x turnover.  But that brings me back to the original point. In the market microstructure literature market impact generally has been found to scale linearly or even sub-linearly for net volume executed.   If I alternate between thousands of 1 lot buy and sell orders, it would be very difficult for me to move the market because the market impact of every one of my buy orders roughly cancels the market impact of my almost exactly equal number of sell orders.   There might be a higher-order mechanism at work, but I'm genuinely curious what you think it might be. How could strategies that attain such small net positions have such out-sized impact on market direction? "I would change that statement to ""very few people can CONSISTENTLY beat the market "". Successful strategies will get piled into and reduce returns. Markets will pick up inefficiencies, but at the same time they do exists. Tons of interesting reading especially in regards to value. Is there a risk premium that we don't know for value? Or is it a market behavior thing?" It is not unheard of. Celebrity investors such as Warren Buffet and Carl Icahn gained notoriety by more than doubling investments some years, with a few very stellar trades and bets. Doubling, as in a 100% gain, is actually conservative if you want to play that game, as 500%, 1200% and greater gains are possible and were achieved by the two otherwise unrelated people I mentioned. This reality is opposite of the comparably pitiful returns that Warren Buffet teaches baby boomers about, but compounding on 2-5% gains annually is a more likely way to build wealth. It is unreasonable to say and expect that you will get the outcome of doubling an investment year over year. Stocks in the Weimar hyperinflation are discussed in When Money Dies. I don't own a copy of the book but here is a link to a blog post about it. Speculation on the stock exchange has spread to all ranks of the   population and shares rise like air balloons to limitless heights Basically, the stock market did very well (i.e. the US dollar value of stocks increased quite a lot. Of course, the price of everything increased if measured in marks.) Quote from the article: Bottom line: In marks, stocks had an amazing run. Even in USD they had   a nice runup. It makes sense that the stock market would skyrocket because (a) if  money has no value, then people will want to replace money with tangible things like goods, and since a stock represents a share in the factories and things which a company owns, it makes sense that you would want them and (b) if money has no value anyway, why not gamble with it? I would be interested to hear what happened in other hyperinflations. It certainly creates an opportunity for the re-distribution of wealth.  Money will be transferred from insurance companies to construction companies.  Businesses that go under will be replaced by ones that survived. Some companies will make a profit out of this, but as you have already figured out, no new wealth is created by the disaster.  (Although lots has been destroyed, so we are looking at a net loss.) Over the last 100 years this has happened twice. It cant be considered an outlier. Especially considering the misery is far from over, euro crisis, looming pension crisis, food crisis, etc. There are a lot of things far from resolved. An event that happens once every 50 years is hardly an outlier just unlikely. "https://en.wikipedia.org/wiki/Irrational_exuberance  &gt; Clearly, sustained low inflation implies less uncertainty about the future, and lower risk premiums imply higher prices of stocks and other earning assets. We can see that in the inverse relationship exhibited by price/earnings ratios and the rate of inflation in the past. But how do we know when irrational exuberance has unduly escalated asset values, which then become subject to unexpected and prolonged contractions as they have in Japan over the past decade?  &gt; — ""The Challenge of Central Banking in a Democratic Society"", 1996-12-05" "Stocks ""go up 5-7% every year. This has been true for the last 100 years for the S&P500 index...."" This was true in the 20th century in America. It was not true (over the whole century) for other major countries like Germany, Russia, Japan, or China. (It was more or less true for Britain and certain Commonwealth countries like Australia and Canada.) A lot of this had to do with which countries were occupied (or not) during the two world wars. In one of his company's annual reports, Warren Buffett pointed out that the U.S. standard of living went up 6-7 times in the 20th century, that this was unprecedented (and might not be repeatable in the 21st century). The performance of the U.S. stock market in the past century is representative of those (and other) past facts. If a different set of facts prevails going forward, the U.S. stock market would be reflective of those ""different"" facts."