Stock investors have a lot of terminology to learn while also learning lots of stock-related math. It can be important to pay attention when an analyst names an "underweight stock," especially if it's one you own.

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Definition

What is an underweight stock?

The term "underweight stock" is a bit of a grandiose phrase for something that's more of a general notion. When a stock is underweight, it simply means that it's not expected to perform as well as other stocks that it's being compared to -- but that's where the rub comes in.

An underweight stock, when compared to its own industry, may be an overweight or even-weight stock when compared to the rest of its index, or vice versa. So, when you see that a stock you're holding is now underweight, you should ask yourself, "Compared to what?" And if that comparison doesn't matter to your investing thesis, don't sweat it.

What it means

What does an underweight recommendation mean?

Many people assume an underweight recommendation for a specific stock means the same as a "sell" recommendation. It really doesn't. An underweight stock is underweight in relation to something (what that something is is wholly based on how it's being analyzed), but that doesn't mean it's not worth keeping.

An underweight stock assessment is a recommendation about how your entire portfolio should be balanced. An underweight stock recommendation doesn't mean the stock itself is actually in poor shape; it's a recommendation to reduce its weight in your portfolio.

So, if you don't hold this stock in your portfolio, it's a recommendation that doesn't mean a lot to you. If you do, and you choose to follow the recommendation, you'd rebalance your portfolio to have less weight on that particular stock, either by purchasing more of other stocks or by selling some of the stock.

Over vs. underweight

Overweight vs. underweight

If an underweight stock is a stock that's underperforming on some metric when compared to something else, like its industry or its index, an overweight stock is a stock that's overperforming compared to whatever metric you're looking at. So, an overweight recommendation is a recommendation to rebalance your portfolio by increasing the weight of the portfolio in that stock -- not necessarily a recommendation to buy.

Sometimes, a stock can be both underweight and overweight at the same time, which can be confusing for investors. It's important to consider what the stock is being compared to to determine if it's under- or overweight and how that aligns with your investing goals. Once you determine what the weighting means for you, you can figure out if you want to rebalance or not.

What to do about it

What to do with underweight stocks

Let's say that you have a stock in your portfolio, ABC Inc. You've been an investor in ABC Inc. for a while, and you generally believe the company is doing well and all of its metrics are within the parameters of your investing thesis. All in all, it's performing as you expect it should.

However, you read online that ABC Inc. is an underweight stock now, and that has you questioning everything about your investing decisions, even though ABC Inc. has been performing well for you. Here's how to deal with that underweight rating:

  • Ask, "Compared to what?" Figure out what the underweight rating is actually saying. Is ABC Inc. underweight compared to the S&P 500? Is it underweight compared to its industry? Is it underweight compared to companies that aren't as much like it as they may seem at first glance?
  • Evaluate your investing thesis. Are you trying to beat the industry or other grouping that ABC Inc. is in across the shorter term? Or do you have ABC Inc. because you believe it has much longer-term potential, perhaps once a flagship product in development is launched? If holding ABC Inc. is still in line with your investing thesis, there may be no cause for concern.
  • Decide if you want to underweight the stock. Are you happy with the performance of your portfolio? Have you checked the company's recent filings? Do you feel like ABC Inc. is a company you would want to bank your future on? Remember, a stock can be simultaneously under- and overweight, and that could be the case with your ABC Inc. holdings. The choice is yours.
  • Act, or don't act. If you choose to act, you can sell some of your stock in ABC Inc. or you can simply rebalance your portfolio by adding more stocks of other types so that ABC Inc. doesn't make up such a large percentage of your portfolio. Or don't act. It's still your portfolio at the end of the day, and you are the one who will ultimately deal with the results of your decisions.

Related investing topics

Just because one analyst says that a stock is underweight doesn't mean you have to act on it. This is simply a way to alert investors that someone has an opinion on the value and future performance of a particular stock. Sometimes, it's glaringly obvious that the stock is in trouble. A lot of times, however, it's a much more gray area. Whether the underweighting turns out to be accurate or not will depend on a million factors, many of which are unknowable at the time of the weighting. For example, no one can really predict where the global economy or state of geopolitics will be in a year.

As with many things in life, when it comes to underweighted stocks, trust but verify.

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