BOND YIELDS UP: Investors pushed up Spanish borrowing rates past 7 percent, to the levels where Ireland, Portugal and Greece sought bailouts. Investors are worrying about Spain's fundamental economic problems.

THE NUMBERS: The interest rate on Spain's 10-year bonds hit a fresh high of 7.18 percent and closed at 7.12 percent. Stocks plunged 3 percent on Madrid's main index.

THE BACK STORY: The rate reflects what return investors are willing to accept when a country auctions its bonds. If investors' concerns remain and the rates stay high, Spain may have to seek foreign aid.