If your retirement funds are invested in the stock market, you simply can’t afford to ignore the signals the market is sending. Any decisions about selling, or buying the dips, must depend on your own risk tolerance, time horizon and overall financial situation. But the time to consider those things is now — at what could be near the end of the longest bull market in history.

Please note there is some debate about whether this has been the longest bull market. The period from October 1987 to March 2000 is considered by some to be the longest bull. But to accept that as fact, you must ignore a frightening slide that took place in late summer and early fall of 1990, when the Dow Jones Industrial Average slid 19.9 percent from its peak.

Since a bear market is defined as a 20 percent decline, a few nay-sayers don’t accept the decline of 1990 as an interruption of that bullish period. But as I personally recall, it looked and felt like a bear market at the time. And many of my readers will remember the precipitous decline that began in the late summer of 2008 and continued through early March of 2009. That decline took the DJIA down nearly 50 percent to a bottom near 6,700! That was where the current bull market started, in the midst of panic selling.

Please do not confuse a bear market with an economic recession, though frequently they travel together. Many bear markets have started just as the economy looked brightest. So it’s not surprising that the business headlines appear bullish: Unemployment is low, the economy is growing, interest rates are still relatively low, and corporations are still reporting great earnings.

So why be worried about a market decline? That’s the exactly the point. Bear markets tend to start when people are least worried. And they reach bottom when everyone is in panic mode.

Why Worry?

If anyone had ever managed to call the top of a bull market more than once in a lifetime, he or she would be famous and wealthy. Every investment newsletter has its own rationale and indicators for calling market turns. Few have been more successful at calling tops and bottoms than James Stack, who writes the Investech Research newsletter (www.Investech.com). It was ranked No. 1 by the Hulbert ranking service for the long- run period from 1985 through 2016.

In Stack’s latest issue, sent just days ago, he advises subscribers to be wary of an oncoming decline. The headline of this pre-Halloween issue is “A Spooky Market.” Stack says his proprietary “housing barometer” is calling for an imminent downturn in the economy that “could be ugly.” And another proprietary indicator, the “negative leadership composite,” just had a “sudden and swift downturn” that “creates a potentially ominous long-term risk” to the market. Given Stack’s track record, there’s reason to worry about stock prices.

Stack now has his managed accounts down to 60 percent exposure to stocks — the lowest since the last peak. Stack says it isn’t “market-timing” but risk management. And he notes that given the high degree of risk in the market these days, it is prudent to have a large amount of “cash” — Treasury bills or money market accounts — on the sidelines.

What should you do?

The worst time to think about your vulnerability to a stock market decline is when everyone else is panicking. That hasn’t happened yet. But one day it will. So NOW is the time to sit down and review your 401(k) plan. If you receive paper statements, you likely just opened your third quarter statement. That’s the place to start analyzing your exposure to stock market risks.

Sort out your real time horizon for your retirement money. The first is the number of years until you retire. And the second is the number of years you will live after you retire. When you retire, you will no longer be making regular monthly investments. So you can’t take advantage of bargain prices in a market decline. But you’ll also need some growth in the future to offset the effects of inflation. Stocks provide that cushion.

If retirement is a distant number, just promise yourself not to sell. Period. There has never been a 20-year period when you lost money in a diversified investment portfolio of large company American stocks, with dividends reinvested — even adjusted for inflation. So keep contributing and ride out the next bear market. For sure there will be one.

But if you’re in, or near, retirement, act now — while you still have profits to protect. Sell down to the “sleeping point.” That’s the Savage Truth.