Rising interest rates are considered bad for stocks because they raise the cost of doing business and depress corporate earnings and because higher yields make bonds relatively more attractive than stocks to investors.

To finance deficits, the government must sell bonds to investors, competing for capital that could otherwise be used to invest in stocks or corporate bonds. Government borrowings raise long-term interest rates, stifling economic growth.

Investors favor steel stocks due to attractive price-earnings ratios and high dividend yields.

Volatility may be rising simply because investors must digest more information every day.

It's one of the fundamental principles of the stock market: When interest rates go up, stocks go down. And along with financial companies and cyclicals, technology companies - with their sky-high price-to-earnings multiples - should be among the biggest losers in an environment of rising rates.

Emerging market stocks were hit hard today, along with their bonds. Lingering fears over higher U.S. interest rates triggered profit-taking again, one day after we saw some good rallies.