New York(CNN Business)Stocks kicked off October with more treats than tricks for investors. The market rallied to begin the fourth quarter, despite growing worries about the financial health of European banking giant Credit Suisse and weak economic data.

The Dow rose more than 600 points, or 2.1% in late morning trading. The Nasdaq and S&P 500 were up 1.4% and 1.9%, respectively. Stocks ended September (and the third quarter) with a resounding thud on Friday.

In a sign of how volatile the market is, all but one of the 30 Dow stocks were higher midday Monday...after they all finished lower Friday. (Johnson & Johnson (JNJ) was Monday's lone laggard.) Investors are increasingly worried about inflation and how the Federal Reserve's aggressive rate hikes to control surging prices could eventually tip the economy into a recession.

Stocks are still down sharply this year. And the CNN Business Fear & Greed Index, which measures seven indicators of investor sentiment, remains at Extreme Fear levels. But Monday's market rebound might be a perverse "bad news is good news" rally.