Should you sell Hologic (Nasdaq: HOLX) 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 Hologic, ready to evaluate its price, valuation, margins, and liquidity. Let's get started!

Don't sell on price
Over the past 12 months, Hologic has risen 41% versus an S&P 500 return of 13.7%. Investors in Hologic 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 Hologic. For historical context, let's compare Hologic'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

Hologic $22.30 $23.24 $36.40
China Medical Technologies (Nasdaq: CMED) $11.76 $14.45 $57.50
Myriad Genetics (Nasdaq: MYGN) $22.69 $24.15 $47.10
Qiagen (Nasdaq: QGEN) $21.39 $22.20 $24.00

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

Hologic 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, let's look at the gross margin 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 Hologic's gross margin over the past five years:

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

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

Hologic 4 3.2
China Medical Technologies 4 27.4
Myriad Genetics 4 8.2
Qiagen 3 3.5

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

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

Here, short interest is at a mere 3.2%. This typically indicates that few large institutional investors are betting against the stock.

Now, let's study Hologic'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.

Hologic 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. 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. Hologic is currently above this level, at 50.9%.

The last metric I like to look at is the current ratio, which lets investors judge a company's short-term liquidity. If Hologic 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, Hologic has a current ratio of 2.85. This is a healthy sign. I like to see companies with current ratios equal to or greater than 1.5.

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

The final recap

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

Remember to add Hologic 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.

Jeremy Phillips does not own shares of the companies mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.