[wasfgwp]

It was certainly not flat. There was a lot of volatility.

> Not sure where you've read that it was

Well.. I looked at the charts. The bottom was few months after Pearl Harbor and pretty much straight up after that. It certainly did much better after US joined than while it was staying out..

[strictnein]

I should have been clearer. From September 1939 - May 1945 (when Germany surrendered), the stock market barely changed:

   September 1939: DJIA was 152.54
   May 1945: DJIA was 168.30

A ~10% increase over almost 6 years is way below average and well below inflation for that time period.

> The bottom was few months after Pearl Harbor and pretty much straight up after that

I mean, you've now picked the bottom of the market as your starting point (and not the start of WW2), so by definition it goes up after that.