The financial press will cook up dozens of reasons why the market fell so hard, so fast today (the Dow was down over 500 points or over 4% before finding some footing). Most will point toward China and tell you that nothing has changed since yesterday, stay the course. But something has changed. High-risk assets are finally done leading the market. The music has stopped, and investors are looking for chairs.

Downplaying risk and focusing exclusively on upside is why fund investors have sunk billions into higher-risk fund categories like emerging markets, Asia, Latin America, and high-yield bonds. It’s why an ETF like iShares FTSE/Xinhua China (FXI) has brought in billions in recent months.

As of 1:17 p.m. today, a China fund, Oberweis China Opportunities Fund (OBCHX), is the fourth most viewed fund page (out of more than 20,000) on MAXfunds.com. This tells you more about the causes of today’s drop than all the financial analysis you’ll read about the rest of the week.

Fund investors have a bad habit of getting most excited about a certain sector or fund category shortly before in sinks. The last time we saw big fund inflows was early in 2006, and in the following months the U.S. stock market slipped, and emerging markets flat out tanked –though both came back later in the year.

This year fund investors have already put around $40 billion into stock funds – most of it into international funds, and a lot of that into emerging markets.

Nobody knows where the market is going in the short run, but it is likely that all the fund categories attracting the most money early this year will perform the worst in coming months. Maybe this isn’t the end of the great high risk asset bull market, but today’s action shows investors the risk of adding new money late in the game.