Back in 2021, Keith Gill wasn’t well known. A video game enthusiast, he liked to spend time in his basement, day-trading and making videos. But with his online persona, Roaring Kitty, Gill drew a following that reached into the millions. He used that platform to direct attention to the shares of video game retailer GameStop, which was nearing insolvency.

Gill’s videos drew enough attention in 2021 to cause a “short squeeze” in GameStop shares. The result: At least one hedge fund, Melvin Capital, lost billions and shut down as a result. And since Gill was on the other side of these trades, he netted millions for himself. But then, as quickly as he had appeared, Gill dropped off the radar.

In recent months, however, Gill has emerged from hibernation. Picking up where he left off, Gill renewed his pitch for GameStop shares, causing the stock to jump 340% during one 10-day stretch in May.

For many, Gill’s reemergence—and his ability to move markets—are a worrying sign. Veteran investor Jeremy Grantham has argued that “crazy behavior” like this is a reliable gauge of risk in the market.

GameStop isn’t the only such data point. Bitcoin recently arose from a multi-year slump to hit a new all-time high. Other so-called meme stocks, including movie theater operator AMC, have also seen their share prices jump in ways that seem irrational. More mature stocks have moved higher as well. The price-to-earnings (P/E) ratio of the S&P 500 Index is nearing 21—quite a bit above its 40-year average of just 16.

Putting these data points together, many investors are starting to ask: Should we worry?

One answer to this question—and the answer I would normally offer—is that making market forecasts is so difficult that the best course of action is to simply stay the course, to avoid trading in an attempt to beat the market. As the late Jack Bogle used to say, “Don’t do something. Just stand there.” I agree with this sentiment, but it’s also worth taking a closer look. Why is it that forecasting is so difficult?

Consider the market today, and what we know about it. For starters we know that the price-to-earnings ratio is above average. We also know that unemployment is low and that inflation has been coming down. We know that interest rates are at 15-year highs but that there’s the expectation they’ll soon drop.

We know all these things as they stand today. The problem, however, is that we don’t know where they’re going next. And we don’t know how a long list of other unknowns will turn out—including a presidential election in less than six months, and multiple wars. Those are what we might call the “known unknowns,” and they’re just part of the story.

Oftentimes, the real drivers of the market are the unknown unknowns—events that aren’t on our radar at all right now. Think back five years, for example. While scientists understood the risk of a pandemic, ordinary people weren’t focused on it at all. That’s a big part of why Covid impacted markets so quickly and so severely. Events that appear out of nowhere tend to have the most significant impact on the market. But everyday investors have no idea when—or if—these risks will appear.

To put it another way, the market indicators that we see today represent just a sliver of what will actually happen in the future. And the rest of the picture—what the future will actually look like—may turn out better, worse or about the same as our best guess right now.

This would make forecasting hard enough. But still, it’s just part of the equation—because any data that we do have is still subject to interpretation. Whether it’s a quantitative measure like a P/E ratio or a qualitative assessment like Grantham’s “craziness” indicator—market information is, to a great degree, in the eye of the beholder. How we receive financial information is a function of each individual’s mindset. In simple terms, each of us could be plotted on a spectrum. At one end would be those whose reaction to most crises is to say, “this too shall pass.” At the other end of the spectrum would be those who panic with each new crisis.

Where we each fall on this spectrum is, in turn, a function of several other factors. To some degree, it’s innate; some are simply more fearful than others. Our posture toward risk is also affected by our experiences—first as children, watching our parents, and then as adults, managing our own finances. And we’re affected by how much we know about a particular topic. The result: Any two people can see the same set of data and arrive at very different conclusions.

But those are just the internal factors. We are also affected by the wider world and by the opinions of others, including, especially, the media—what’s in the news, as well as the news sources we choose. A key challenge with all of this is that what happens to be in the news, or what’s happened most recently, isn’t necessarily what’s most important, or what poses the most risk to investors. Rather, what’s in the news is simply a function of what editors choose to emphasize.

I don’t mean to single out journalists. Consumers of financial information play a part too. In the past, I’ve talked about the concept of “single stories.” Faced with a complicated world, our minds naturally look for shortcuts in understanding things. As a result, we simplify stories in our minds so we can develop an opinion on it and move on. But sometimes these single stories are oversimplified.

A related concept is “rational ignorance.” The idea here is that there’s simply too much going on in the world for any one person to understand. There just isn’t enough time. As a result, counterintuitive as it may seem, it’s rational to choose to remain ignorant of certain things—perhaps most things.

The bottom line: As investors, we are at a distinct disadvantage in guessing how the future will turn out. Not only do we have limited information, but even the information we have is subject to interpretation. Is the reemergence of Keith Gill a warning sign, or just a distraction? There’s no way to know.

It’s for these reasons that I believe investors are best served by avoiding forecasting. As I discussed a few weeks ago, even when trends in the data look reliable, or when a particular outcome looks like a foregone conclusion, investors’ best bet, I believe, is to nonetheless hedge our bets—to avoid ever being too sure.