Without a doubt, 2016 is shaping up to be a great year for stocks. As I write, the S&P 500 is on track to post double-digit total returns by the time the calendar year closes, and the big stock index is back within grabbing distance of fresh all-time highs in September.

But don't let that steady ascent in the broad market make you complacent. In spite of the price trajectory of the broad market overall, a pretty big chunk of this market is actually flailing right now.

For instance, while nearly one in two S&P 500 components are up 10% or more year-to-date, another third are actually down since the start of the year. And that big performance gap among S&P components becomes a big problem if you own any "toxic" stocks in your portfolio. The good news is that some of the biggest potential underperformers are tipping investors off ahead of time this fall.

To figure out which stocks to steer clear of, we're turning to the charts today for a technical look at five stocks that could be toxic to own in the month ahead.

For the unfamiliar, technical analysis is a way for investors to quantify qualitative factors, such as investor psychology, based on a stock's price action and trends. Once the domain of cloistered trading teams on Wall Street, technicals can help top traders make consistently profitable trades and can aid fundamental investors in better entry and exit points.

Just so we're clear, the companies I'm talking about today are hardly junk. By that, I mean they're not next up in line at bankruptcy court -- and many of them have very strong businesses. But that's frankly irrelevant to what happens to their stocks; from a technical analysis standpoint, sellers are shoving around these toxic stocks right now. For that reason, fundamental investors need to decide how long they're willing to take the pain if they want to hold onto these firms in the weeks and months ahead. And for investors looking to buy one of these positions, it makes sense to wait for more favorable technical conditions (and a lower share price) before piling in.

So without further ado, let's take a look at five "toxic" stocks to sell.

Eastman Chemical

Up first on the list is $10 billion chemical maker Eastman Chemical (EMN - Get Report) . Eastman has been all over the place this year, starting things off with a rally only to roll over and sell off 15% from its May highs. The problem for investors is that Eastman is showing off a bearish price setup following that correction -- and it means that shares could be in store for a second leg lower from here.

Eastman is currently forming a descending triangle, a bearish continuation pattern that's formed by horizontal support down below shares at $64, and downtrending resistance to the topside. Basically, as Eastman bounces in between those two technically important price levels, this stock has been getting squeezed closer and closer to a breakdown through that $64 price floor. If and when that happens, we've got a major sell signal in this chemical stock.

Relative strength, which measures Eastman's price performance versus the rest of the stock market, adds some extra evidence for a continued downside move here. Our relative strength line is still holding onto its downtrend from May, signaling the fact that Eastman continues to materially underperform the broad market even now. If $64 gets busted, it's time to sell Eastman Chemical.

Clorox 

That's exactly what happened this week in Clorox (CLX - Get Report) . This $16 billion household products stock had been moving higher at the start of the summer, but shares rolled over and started forming a descending triangle setup in the last couple of months. The pattern triggered a sell signal on Wednesday, when Clorox violated prior support at $130.

The price pattern in Clorox isn't 100% textbook. Typically the descending triangle pattern is a continuation pattern that comes after an initial down move, not a reversal pattern like we're seeing on Clorox's chart. Ultimately, however, the pattern in Clorox may not be "textbook," but it's tradable. And we saw that play out with a second day of relatively stiff selling yesterday.

From here, expect an upward correction in Clorox before shares continue their move to the downside. Prior support at $120 is the next meaningful price floor on the chart, which implies we're still likely to see about a 5% downside move from here.

If you're looking for an opportunity to buy the dip in Clorox, this isn't it. Wait for shares to catch a bid and establish another support level before buying shares. Clorox looks toxic in the near-term.

Kimberly-Clark 

The last year has come with some outstanding price performance for shares of paper product maker Kimberly-Clark  (KMB - Get Report) . In the trailing 12 months, this $44 billion company has rallied more than 21% higher, leaving the rest of the S&P 500 in its dust. But investors might want to start thinking about taking some of those recent gains off the table here; Kimberly-Clark is beginning to look "toppy" in the long-term.

Kimberly-Clark is currently forming a double top, a bearish reversal setup that looks just like it sounds. The price setup is formed by a pair of swing highs that peak at approximately the same price level. The sell comes on a breakdown through the low that separates those twin highs. For KMB, that breakdown level comes in at $122.50 support.

Remember to be reactionary with the Kimberly-Clark trade -- or with any of the other price setups on our list, for that matter. Technical analysis is a risk management tool, not a crystal ball. That means that stock doesn't actually trigger a sell signal until that $122.50 price floor gets materially violated first. Until then, Kimberly-Clark is waving a caution flag, but it's not an outright sell signal until buyers lose the battle at $122.50.

HCA Holdings 

Things are looking pretty straightforward for shares of $30 billion hospital operator HCA Holdings  (HCA - Get Report) . This big health care stock kicked off 2016 in rally mode, but it's been aiming lower ever since the end of April, when shares started bouncing their way lower in a well-defined downtrend. Don't get too excited about the recent rebound in shares of HCA since mid-August; this stock looks ready to get knocked down again at the top of its price channel.

HCA's downtrend is identified by a pair of parallel trendlines that have contained all of this stock's price action since April Put simply, every test of the top of the channel has given sellers their best opportunity to get out before this stock's subsequent leg lower. And shares are moving back up toward resistance for a fifth time this week.

Waiting for this most recent bounce lower before clicking "sell" is a critical part of risk management for two big reasons: It's the spot where prices are the highest within the channel, and alternatively it's the spot where you'll get the first indication that the downtrend is ending. Remember, all trend lines do eventually break, but by actually waiting for the bounce to happen first, you're confirming that sellers are still in control before you unload shares of HCA.

Vulcan Materials

Last on our list of potentially toxic trades is $15 billion construction materials maker Vulcan Materials (VMC - Get Report) . Vulcan has been an outstanding performer in 2016, up more than 17% since the start of January. But now, as we round the corner to the fall months, that rally is beginning to show some major cracks. Here's how to trade it:

Vulcan Materials has been forming a textbook example of a head and shoulders top, a reversal pattern that signals exhaustion among buyers. It's formed by two swing highs that top out at approximately the same level (the shoulders), separated by a higher high (the head). The sell signal comes on a breakdown through VMC's neckline, down at $115. Shares busted through that price level this week.

From here, Vulcan just opened up a lot of downside risk. The minimum downside objective from VMC's price pattern is about a 10% selloff, but shares could actually retreat more if they establish a new trend to the downside. For that reason, it makes sense to stay away from the long side of Vulcan Materials until shares are able to start establishing some higher lows again.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.