NEW YORK (TheStreet) -- With stock market history full of famous examples of stocks that very quickly blew up, here I examine three particularly vulnerable stocks that should be avoided at all costs. What's worse, these stocks are commonly found in the retirement accounts of millions of investors.

The following three stocks pose a clear and present danger to your portfolio. If you want to see a list of the absolute worst stocks you can own right now, take a look at this report called 29 Dangerous Stocks: Sell Now!. Inside, you'll see a full list of the market's most overvalued stocks, and learn the process you can use to keep avoiding them in the future. Click here for a copy.

A host of factors loom over the global economy that could trigger a major stock market plunge: China's precarious stock market and flagging economy; debt woes and a migrant crisis in the euro zone; violence in the Middle East; political dysfunction in Washington, D.C. The list goes on. The following stocks are already vulnerable on their own accord, but they'd get dragged down the hardest in any market drop. Let's take a look.

1. Facebook (FB) - Get Report

On our list of endangered species, you could include just about any overhyped social media stock, such as LinkedIn (LNKD) , Twitter (TWTR) - Get Report or Yahoo! Inc. (YHOO) .

But I think Facebook(FB) - Get Report poses the worst danger, because of its nosebleed valuation combined with investor complacency.

With a whopping market cap of $262 billion, Facebook is ostensibly thriving. Every strategy of company founder and CEO Mark Zuckerberg seems to be working. The company's revenue took off in 2014 and exceeded $12.4 billion.

As the progenitor of social media, Facebook is now heavily investing in the purchase of promising new technology companies. It's also emphasizing mobile and the "Internet of things." Just like a company called...MySpace.

Sure, Facebook now has more than 1 billion monthly active users. But most of these users are millennials, a customer base that's fickle and suffers from a collective short attention span. At the same time, teens are leaving Facebook at the rate of about 1 million a year, for "cooler" social media venues such as Snapchat and Instagram (which Facebook owns).

Facebook now sports an outrageously high trailing 12-month price-to-earnings price-to-earnings ratio of 95, compared to the average price-to-earnings ratio of 47.4 for Internet information providers and 20.16 for the technology sector as a whole. All it would take is for one disruptive technology to send Facebook falling on its face.

2. Hewlett-Packard Co. (HPQ) - Get Report

Founded in 1939 in the proverbial garage in Palo Alto by William Hewlett and David Packard, this erstwhile industry leader saw its market share decline by nearly 41% during the 2008-2009 global financial crisis, as consumers reduced their purchases of computers and related consumer goods.

The smartphone revolution further hammered HP's sales and stock. And unlike legacy chipmakers such as Intel Corp. (INTC) - Get Report , HP never learned to make the adjustment.

Grievous missteps by former HP CEO (and current GOP presidential hopeful) Carly Fiorina didn't help either, when in 2002 she oversaw what was then the largest technology sector merger in history, in which HP acquired rival PC maker Compaq for $25 billion. The merger was a disaster from which HP never recovered.

Another bungled deal that continues to haunt Hewlett-Packard is the company's $11 billion purchase of British software concern Autonomy in 2011, under the oversight of former HP CEO Léo Apotheker. HP's stock price fell by more than half during Fiorina's six-year tenure and by about the same during Apotheker's year-long stint. Both were forced by the board to resign.

According to research firm IDC, global PC shipments in the most recent quarter fell 10.8% from the year before. The transition away from PCs and toward mobile devices will only further strand HP, as it flounders like a mastodon in the La Brea tarpits.

Hewlett-Packard stock is now more than 28% off its all-time high this year. With a strong greenback hurting exports and a global economy increasingly on shaky ground, you should sell this dinosaur now.

3. Schlumberger (SLM) - Get Report

With central offices in Houston and Paris, Schlumberger's services include offshore drilling and hydraulic fracturing, or "fracking," a process under which water, sand and chemicals are injected underground to tear loose hydrocarbons that are trapped within shale rock.

That sounds good, until you drill deeper and realize that the company has made huge and expensive expansion efforts in China -- a bet that went awry ever since the Chinese stock market crashed on Monday, August 24, a day now known as "Black Monday."

Schlumberger generates two-thirds of its revenue outside of North America, the highest ratio among its top competitors. This overseas diversification has been transformed from a plus into an albatross, as European growth stagnates and the Chinese economy continues to flounder.

Meanwhile, as the Saudis continue their price war and the globe remains awash in a glut of production, the price of oil continues to hover well below $50 a barrel, with no upward momentum in sight.

Schlumberger's stock has dropped nearly 20% from its high this year, with further declines ahead. Caveat emptor.

As you can see, Facebook, Hewlett-Packard, and Schlumberger all look like stocks to avoid right now. However, if you want to see a list of the absolute worst stocks you can own, take a look at this report called 29 Dangerous Stocks: Sell Now!.

John Persinos is an editor and investment analyst at Investing Daily. At the time of publication, the author held no positions in the stocks mentioned.