While market worries abound, a recent article in The New York Times argues against trying to predict when the bull market will end or making trades based on those predictions. It adds, however, that there are those who “deserve to worry at any particular moment: those who will need most or all of their investment money soon.”

It’s difficult to know, the article says, how much is the right amount to have invested in stocks at any given moment, but a good place to start is for an investor to determine “how comfortable you are with the possibility of losing some money” and to decide what they are willing to give up to in the event that they do.

The author offers several different scenarios as examples of how investors can accomplish this exercise along with assumptions concerning different market scenarios. “It’s tempting to consider how you reacted to stock market declines at the end of the last decade in figuring out how you might react in the future. If you had decent nerves back then when your child was in preschool, perhaps you were betting that you were buying stocks on sale.” But as children get closer to college age, he argues, risk tolerance becomes severely compromised.

The article concludes that while some investors can face the possibility of market losses by “earning more, saving more or spending less,” it adds, “many of us aren’t that lucky.” Imagining the pain of an equity portfolio loss, he claims, might be the best they can do.