Should you sell General Mills (NYSE: GIS) today?

The decision to sell a stock you've researched and followed for months or years is never easy. If you fall in love with your stock holdings, you risk becoming vulnerable to confirmation bias -- listening only to information that supports your theories, and rejecting any contradictions.

In 2004, longtime Fool Bill Mann called confirmation bias one of the most dangerous components of investing. This warning has helped my own personal investing throughout the Great Recession. Now, I want to help you identify potential sell signs on popular stocks within our 4-million-strong Fool.com community.

Today I'm laser-focused on General Mills, ready to evaluate its price, valuation, margins, and liquidity. Let's get started!

Don't sell on price
Over the past 12 months, General Mills has risen 1.4% versus an S&P 500 return of 13.7%. Investors in General Mills are no doubt disappointed with their returns, but is now the time to cut and run? Not necessarily. Short-term underperformance alone is not a sell sign. The market may be missing the critical element of your General Mills investing thesis. For historical context, let's compare General Mills' recent price to its 52-week and five-year highs. I've also included a few other businesses in the same or related industries:

Company

Recent Price

52-Week High

5-Year High

General Mills

$36.33

$38.98

$39.00

Kraft Foods (NYSE: KFT)

$31.44

$32.67

$37.20

Kellogg (NYSE: K)

$51.50

$56.00

$58.50

HJ Heinz (NYSE: HNZ)

$48.80

$50.77

$53.00

Source: Capital IQ, a division of Standard & Poor's.

As you can see, General Mills is down from its 52-week high. If you bought near the peak, now's the time to think back to why you bought it in the first place. If your reasons still hold true, you shouldn't sell based on this information alone.

Potential sell signs
First up, we'll get a rough idea of General Mills' valuation. I'm comparing General Mills' recent P/E ratio of 15.3 to where it's been over the past five years.

Source: Capital IQ, a division of Standard & Poor's.

General Mills' P/E is lower than its five-year average, which could indicate the stock is undervalued. A low P/E isn't always a good sign, since the market may be lowering its valuation of the company because of less attractive growth prospects. It does indicate that, on a purely historical basis, General Mills looks cheap.

Now, let's look at the gross margins trend, which represents the amount of profit a company makes for each $1 in sales, after deducting all costs directly related to that sale. A deteriorating gross margin over time can indicate that competition has forced the company to lower prices, that it can't control costs, or that its whole industry's facing tough times. Here is General Mills' gross margin over the past five years:

Source: Capital IQ, a division of Standard & Poor's.

General Mills is having no trouble maintaining its gross margin in a tight range. This is solid news; however, General Mills investors need to keep an eye on this over the coming quarters. If margins begin to dip, you'll want to know why.

Next, let's explore what other investors think about General Mills. We love the contrarian view here at Fool.com, but we don't mind cheating off of our neighbors every once in a while. For this, we'll examine two metrics: Motley Fool CAPS ratings and short interest. The former tells us how Fool.com's 170,000-strong community of individual analysts rate the stock. The latter shows what proportion of investors are betting that the stock will fall. I'm including other peer companies once again for context.

Company

CAPS Rating (out of 5)

Short Interest (% of Float)

General Mills

****

0.7

Kraft Foods

****

1.3

Kellogg

***

2.3

HJ Heinz

****

2.7

Source: Capital IQ, a division of Standard & Poor's.

The Fool community is rather bullish on General Mills. We typically like to see our stocks rated at four or five stars. Anything below that is a less-than-bullish indicator. I highly recommend you visit General Mills' stock pitch page to see the verbatim reasons behind the ratings.

Here, short interest is at a mere 0.7%. This typically indicates few large institutional investors are betting against the stock.

Now, let's study General Mills' debt situation, with a little help from the debt-to-equity ratio. This metric tells us how much debt the company's taken on, relative to its overall capital structure.

Source: Capital IQ, a division of Standard & Poor's.

General Mills has been taking on some additional debt over the past five years. When we take into account unchanged total equity over the same time period, this has caused debt-to-equity to increase, as seen in the above chart. Based on the trend alone, that's a bad sign. I consider a debt-to-equity ratio below 50% to be healthy, though it varies by industry.  General Mills is currently above this level, at 124.9%.

The last metric I like to look at is the current ratio, which lets investors judge a company's short-term liquidity. If General Mills had to convert its current assets to cash in one year, how many times over could the company cover its current liabilities? As of the last filing, General Mills has a current ratio of 1.08. General Mills could cover its current liabilities, but it's still below a healthy level of 1.5.

Finally, it's highly beneficial to determine whether General Mills belongs in your portfolio -- and to know how many similar businesses already occupy your stable of investments. If you haven't already, be sure to put your tickers into Fool.com's free portfolio tracker, My Watchlist. You can get started right away by clicking here to add General Mills.

The final recap

General Mills has failed only two of the quick tests that would make it a sell. This is great, but does it mean you should hold your General Mills shares? Not necessarily. Just keep your eye on these trends over the coming quarters.

Remember to add General Mills to My Watchlist  to help you keep track of all our coverage of the company on Fool.com.

If you haven't had a chance yet, be sure to read this article detailing how I missed out on more than $100,000 in gains through wrong-headed selling.