Should you sell McKesson (NYSE: MCK) 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 McKesson, ready to evaluate its price, valuation, margins, and liquidity. Let's get started!

Don't sell on price
Over the past 12 months, McKesson has risen 21.4% versus an S&P 500 return of 13.7%.  Investors in McKesson have every reason to be proud of their returns, but is it time to take some off the top? Not necessarily. Short-term outperformance alone is not a sell sign. The market may be just beginning to realize the true, intrinsic value of McKesson. For historical context, let's compare McKesson's 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

McKesson $78.77 $81.00 $81.00
Medco Health Solutions (NYSE: MHS) $55.53 $65.39 $66.90
Cardinal Health (NYSE: CAH) $40.65 $43.00 $76.20
AmerisourceBergen (NYSE: ABC) $39.64 $40.91 $40.90

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

McKesson is basically at its 52-week high. This means we need to dig into the valuation to ensure that these new highs are justified.

Potential sell signs
First up, we'll get a rough idea of McKesson's valuation. I'm comparing McKesson's recent P/E ratio of 19.7 to where it's been over the past five years.

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

McKesson's P/E is higher than its five-year average, which could indicate the stock is overvalued. A high P/E isn't always a bad sign, since the company's growth prospects may also be increasing alongside the market's valuation. However, it definitely indicates that, on a purely historical basis, McKesson looks expensive.

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 is facing tough times. Here is McKesson's gross margin over the past five years:

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

McKesson has been able to grow its gross margin, which tends to dictate a company's overall profitability. This is great news; however, McKesson 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 McKesson. 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

Short Interest (% of Float)

McKesson

*****

1.6

Medco Health Solutions

****

1.2

Cardinal Health

****

0.9

AmerisourceBergen

****

2.0

Sources: Capital IQ (a division of Standard & Poor's) and Motley Fool CAPS.

The Fool community is rather bullish on McKesson. 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 McKesson's stock pitch page to see the verbatim reasons behind the ratings.

Here, short interest is at a mere 1.6%. This typically indicates that few large institutional investors are betting against the stock.

Now, let's study McKesson's 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.

McKesson has been taking on some additional debt over the past five years.  Even with increasing total equity over the same time period, debt-to-equity has increased , 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. McKesson is currently above this level, at 57.4%.

The last metric I like to look at is the current ratio, which lets investors judge a company's short-term liquidity. If McKesson 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, McKesson has a current ratio of 1.10. McKesson could cover its current liabilities, but it's still below a healthy level of 1.5.

Finally, it's highly beneficial to determine whether McKesson 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 McKesson.

The final recap

McKesson has failed three of the quick tests that would make it a sell. Does it mean you should sell your McKesson shares today solely because of this? Not necessarily, but keep your eye on these trends over the coming quarters.

Remember to add McKesson 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 over $100,000 in gains through wrong-headed selling.