The stock market is getting the jitters as this bearish signal flashes red again. Here's why the surge in bond yields is spooking the bulls.

• The bond market is capturing a shift higher in interest-rate expectations, which is bad news for stocks.
• The yield on the 10-year Treasury note breached 4% this week for the first time since November.
• Here's what that means for the broader financial market, and what major investors now expect.

The stock market is fast losing any remnants of its early-year bullish mood, with more evidence suggesting the twin threats of elevated inflation and higher interest rates are very much alive.

Underscoring such risks are the latest developments in the US bond market, which tends to capture the outlook for consumer-price trends and rates much more dynamically.