An article in "The Buzz" in CNN Money on 27.12.12 indicates a retreat from the U.S. market of individual investors similar to that which posters have noted here. Interestingly, high-frequency trading is noted as one of the reasons for the desertion from the market.
I quote:-
"The U.S. stock market has been on a bull run since early 2009. At the same time, individual investors have been pulling billions of dollars out of stocks each year.
As the S&P 500 rallied about 13% during the first eleven months of 2012, individual investors yanked about $152 billion from the U.S. stock market, according to data from EPFR Global, a Boston-based firm that tracks fund flows for both mutual funds and exchange traded funds.
That marks the third year in a row that investors have withdrawn more than $150 billion from U.S. stock mutual funds and ETFs.
While individual investors have been shunning the market, institutional investors, such as hedge funds and pension funds, have been significantly adding to their stock positions. They've poured more than $80 billion into stocks so far this year.
.....The mass exodus from stocks isn't exactly new. While individual investors have been taking money out of the stock markets since 2005, the outflows accelerated considerably beginning in 2010.
Experts have largely pinned the reason for the stock dump on the Baby Boomer generation.
They represent the largest group among retail investors, and after having their portfolios rocked by the dot-com crash and the financial crisis, they've shifted out of stocks and into bonds much earlier than usual as they head into retirement.
.....A lack of confidence among investors across age groups has also been a factor, in the wake of high-frequency trading, and incidents like the May 2010 flash crash , Nasdaq's bungled Facebook IPO (FB) and the Knight trading glitch (KCG)".