When corporations need money, they sometimes turn to the bond market — issuing corporate bonds and selling them to raise some cash. It has been getting more expensive for them to do that. Investors have gotten a little more reluctant to hand over their money. That’s not an alarm bell, but it’s not a great sign either.

Out of all the different nooks and crannies in this whole wide economy where you could put your money, one of the safest places is in a government bond.

“Because the U.S. Treasury in theory will always pay its bills,” said Eric Jacobson, a senior principal with Morningstar. 

Corporations also sell bonds — corporate bonds — to raise money. But they don’t, in theory, always pay their bills. Companies come and they go. Companies default.

“The bond market uses the U.S. Treasury market as a baseline,” Jacobson said. “Everything else in the bond market pretty much is compared to the Treasury bond.”

So whatever interest rate the U.S. Treasury is offering people to invest in the government, McDonald’s or John Deere or Walmart have to beat it to convince anyone to lend them money.

“So a bond trader might say Treasurys plus 1%,” Jacobson said.

And the shakier the company, the more interest it has to promise compared to the government. That difference is called a spread.

“And that gives you an idea of the market’s estimation of how much more credit risk there is,” Jacobson said.

The spread is kind of a measuring stick for shakiness. Which brings us to now. The spreads are the widest they’ve been in six months, especially for riskier companies. The level of general shakiness has increased just a tad.

“There’s a lot more uncertainty that the market is having to confront,” said David Hamilton, head of research for asset management at Moody’s. “Not the least of which are the uncertainty around the impact of tariffs and trade wars breaking out all over the place.”

Bottom line, more vulnerable companies, medium-sized companies, companies with floating interest rates — they are having to pay more interest on their debt. That means more stress for already stressed companies.

“For these middle-size and small-size borrowers, economic growth has been positive, but the burden of the cost of their debt has sort of swamped that positive effect,” said Hamilton.

The good news is that the moves in corporate bond spreads so far have been small by historical standards, and many larger companies are prepared.

“They’ve had very low leverage, balance sheets are in a very good spot, they’ve been cautious,” said Leslie Falconio, head of strategic taxable fixed income at UBS. “The word recession has come back into the picture. It’s not our view that we go into a recession, but we do think growth slows.”

The odds of recession, though, did get bumped up to about 30%, Falconio said.