You don't need to wait for Halloween to see some scary stuff in this market. That's because, despite the fact that a large chunk of the stock market is rallying this fall, another sizable portion of the S&P 500 is doing the opposite. As I write, one in five S&P components is down 7% or more since the start of this year. That's 12.7% underperformance versus the index itself.

So while the S&P may be showing modest gains in 2016, it's really because the individual stocks in the index are either doing great or they're doing awful. Very few fall in between. And it's the awful stocks -- the ones that look toxic to your portfolio -- that you should be paying the most attention to right now. By simply not owning the names that are predisposed to underperform this year, you hugely boost your odds of beating the rest of the market here.

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 for your portfolio 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.

Celanese 

Image placeholder title

At first glance, it's been a pretty unremarkable year for shares of $10 billion chemical company Celanese (CE) - Get Report  . Year-to-date, shares are only down about 1%. That's certainly not performance to be excited about, but it's not dire either. The problem comes when you zoom in on Celanese's chart; more recently, since shares peaked in June, Celanese has shed about 8% of its market value during a timeframe when the S&P has actually been moving higher.

More concerning shares are showing off a price setup that's signaling the potential for a second leg lower in October.

Celanese is currently forming a descending triangle pattern, a bearish continuation setup that's formed by horizontal support down at $61 and downtrending resistance to the top-side. Basically, as Celanese pinballs in between those two technically important price levels, it's been getting squeezed closer and closer to a breakdown through its $61 price floor. When that happens, we've got a clear-cut sell signal.

Relative strength, which measures Celanese's price performance versus the rest of the stock market, adds another red flag to this chart. That's because relative strength has been in a downtrend since the start of the summer, signaling that shares are continuing to underperform the S&P 500 right now. If $61 gets busted, this stock could see a lot more downside before the end of the year. Prior support at $54 looks like the next likely stopping point from there.

Eastman Chemical

Image placeholder title

Celanese isn't the only chemical stock that's showing some cracks this fall -- $10 billion specialty chemical maker Eastman Chemical (EMN) - Get Report  is another. And not totally surprisingly, both charts are showing the exact same potentially toxic price setup. For Eastman, the sell signal comes if shares violate support at $64.

What makes that $64 level in particular so significant? It all comes down to buyers and sellers. Price patterns, such as this descending triangle setup in Eastman, are a good quick way to identify what's going on in the price action, but they're not the actual reason it's tradable. Instead, the "why" comes down to basic supply and demand for shares of the stock itself.

The $64 support level in Eastman is a place where there has been an excess of demand for shares; in other words, it's a spot where buyers have been more eager to step in and buy shares than sellers have been to take gains. That's what makes a breakdown below $64 so significant -- the move would mean that sellers are finally strong enough to absorb all of the excess demand at that price level. Keep a close eye on that $64 level from here.

Toyota Motor 

Image placeholder title

Japanese automaker Toyota Motor (TM) - Get Report  has actually been the sort of stock you'd want to own in recent months. Since the start of July, this $196 billion car stock has seen its share price climb 16% higher. But after a market-beating run, Toyota's rally is starting to show some serious cracks this fall…

Toyota is currently forming a rounding top, a bearish reversal pattern that looks just like it sounds. The price pattern in Toyota indicates a gradual shift in control of shares from buyers to sellers, and it triggers a sell when the support level that defines the bottom of the pattern gets violated. For Toyota, that key support level is down at $114.

One important thing to remember here is that, toxic as Toyota's chart may look, its outcome isn't set in stone yet. Technical analysis is a risk management tool, not a crystal ball. So, like with any of the other trades on our list of stocks today, Toyota doesn't actually become a high-probability downside move until its $114 support level gets violated. Until then, it's waving a caution flag. That said, don't ignore the warning flags in Toyota with shares hovering just above support this week; if $114 gets broken, this stock becomes a sell.

Deutsche Bank

Image placeholder title

You don't need to be an expert technical trader to figure out that $19 billion German financial giant Deutsche Bank (DB) - Get Report  has been a toxic trade this year. Since the calendar flipped to January, DB has sold off in high-profile fashion, tumbling more than 44%. And while the firm remains in the headlines this fall, the price chart tells you just about everything you need to know about buying (or holding) Deutsche Bank here.

Deutsche Bank's selloff has been nothing if not orderly. For almost all of 2016, shares have worked their way lower in a downtrending channel, a price setup formed by a pair of parallel trend lines that have corralled nearly all of this stock's price action. So far, every test of the top of the channel has given sellers their best opportunity to get out before this stock's subsequent leg lower. As Deutsche Bank rebounds towards trend line resistance for a sixth time in October, it makes sense to sell the next bounce off that level.

Waiting for that 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 Deutsche Bank.

Eversource Energy

Image placeholder title

Last up on our list of potentially toxic trades today is $17 billion utility holding company Eversource Energy (ES) - Get Report . Eversource has spent almost all of 2016 forming a classicly bearish price setup -- and shares are testing a violation of the pattern's trigger point today. That means it's make-or-break time for Eversource here.

Eversource Energy has been forming a head and shoulders top, a reversal pattern that signals exhaustion among buyers. The setup is 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 Eversource's neckline, down just below the $53 level. Shares closed slightly below $53 in Thursday's session - and while the violation of this stock's trend line isn't material quite yet, it's close here.

The amount of time that Eversource Energy has spent forming this price pattern is significant too. The pattern started back in early February, making it a very long-term price setup. Long-term price patterns come with equally long-term trading implications when they trigger. If Eversource crosses through $52, this stock's likely downside target is prior support at $47. Buyer beware.

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