Every morning, you'll find plenty of handy explanations from mainstream financial media talking about the issue of the day and somehow linking it to the short-term movements of the market. This morning, China's central bank was the scapegoat du jour, even though the crisis actually began last week and was largely ignored at the time. After suffering big declines last week, the Dow Jones Industrials (^DJI 0.06%) started off the week on the same note, plunging 173 points by 10:50 a.m. EDT.

But the bigger driver of the stock market's recent decline is the strength of its previous advance. Indeed, much of the selling pressure is coming from stocks that were among the biggest gainers during the bull market run. For instance, Hewlett-Packard (HPQ -0.25%) is down 3.2% this morning, but nothing fundamental has changed in HP's turnaround. The plan CEO Meg Whitman has laid out will take years to execute, making single-day volatility a function of traders looking for short-term angles, rather than a meaningful change to its underlying business. Much more reasonable is the argument that the stock's huge upward move in recent months was overblown and that a pullback merely moderates what has been great performance for shareholders.

Similarly, Bank of America (BAC 1.53%) is down about 2.5% despite having taken steps to give the Federal Reserve a plan on how to respond to a potential future financial crisis. The so-called "living wills" for banks like B of A list possible steps that they could take if a shock to the global financial system led to capital problems. To the extent that these documents keep regulators from imposing stricter guidelines, they're positive for B of A. Yet again, after having doubled last year, B of A's stock has arguably gotten ahead of itself.

Finally, beyond the Dow, the real damage is happening not in stocks but in other markets, especially bonds. PIMCO Total Return ETF (BOND -0.25%) is down 1.3%, proving to investors seeking safety that bond investments are far from a secure place to put your money these days. Emerging-market bond investments are taking even more damage, with iShares JPMorgan USD Emerging Markets Bond (NYSEMKT: EMB) plunging 3.5%. When investors try to reduce their risk, the first place they look is in the more aggressive areas where they've put their money. The exodus from emerging markets in both stocks and bonds shows the fear that's rising among U.S. investors -- but that fear is motivated less by the prospects in those countries than by investors' desire to preserve hard-won profits dating back to 2009.