In his latest weekly market commentary, top fund manager John Hussman says four factors are indicating that the U.S. is on the verge of a double-dip recession.

“In every instance we’ve observed these conditions, the U.S. economy has either already been in a recession, or has been within a few weeks of what turned out in hindsight to be the official beginning of a recession,” Hussman writes. “There have been no false signals.”

The four factors:

1: Widening credit spreads: Hussman says this is already occurring.

2: Moderate or flat yield curve: “Virtually any decline” in the 10-year Treasury yield  will make this occur, Hussman says.

3: Falling stock prices: This, of course, has occurred in recent weeks.

4: Moderating ISM and employment growth: The measures Hussman uses for employment growth are moderating;  the ISM growth is not.

“For all intents and purposes, unless the credit spreads, the S&P 500, or the yield curve reverse, a further decline in the Purchasing Managers Index to 54 or below would be sufficient to confirm a ‘double-dip recession’,” writes Hussman. “Note that by itself, such a level might not be particularly troublesome. But in concert with the other evidence we observe, it would be sufficient to complete the syndrome of risk factors.”

Hussman doesn’t recommend that investors who have a disciplined approach and have built their portfolios “to weather a wide range of potential risks” make any drastic changes in light of all of this. “But,” he adds, “if your investment security or future plans would be unacceptably affected by a further, possibly substantial market loss, and particularly if you’ll need the funds in a short number of years, I would suggest getting your risk exposure to the point where you can tolerate negative market outcomes.”