Our technical scanner runs daily across the S&P 500 and Nasdaq 100, measuring a broad range of momentum, trend and volume indicators to identify stocks showing meaningful bullish or bearish pressure. For 18 July 2026, we present the five names generating the highest number of technical sell signals — stocks that, on a purely technical basis, are exhibiting characteristics often associated with further price weakness. A short candidate is a stock where the weight of technical evidence suggests sellers are in control, making it a potential candidate for a short position.
Important risk warning: Short selling carries substantially greater risk than buying a stock. Losses on a short position are theoretically unlimited, since a stock’s price can rise without bound. Forced buy-ins, borrowing costs, and sudden news events can all work against a short seller rapidly. None of the analysis below constitutes financial advice. Always conduct your own due diligence and consider your personal risk tolerance before opening any short position.
1. Centene Corporation (CNC) – 14 technical sell signals
Price: $63.89 | Daily change: -4.08%
View the full technical analysis of Centene Corporation
Centene leads today’s list with 14 bear signals against just 4 bull signals, and a sharp single-day decline of more than 4% underscores the selling pressure. The managed care insurer has had a turbulent period, with CNBC’s Jim Cramer previously describing the stock’s performance in notably harsh terms. That kind of high-profile negative sentiment, combined with a technically deteriorating chart, suggests institutional confidence remains fragile.
On the more constructive side, RBC initiated coverage in early July 2026, arguing that the worst of the company’s 2025 difficulties is now behind it. Prominent investors including David Einhorn have also been adding to positions, and the stock has appeared on several lists of healthcare names with notable insider buying. These are genuine countervailing factors that a short seller should weigh carefully.
Nevertheless, the technical picture is the most bearish of any name in today’s scan. With 14 sell signals firing simultaneously, CNC is clearly under significant chart-based pressure. Shorts should be mindful that any positive earnings surprise or policy development in Medicaid reimbursement could trigger a sharp reversal.
2. F5, Inc. (FFIV) – 12 technical sell signals
Price: $403.41 | Daily change: -4.29%
View the full technical analysis of F5, Inc.
F5 shares fell more than 4% on the day, and the scanner picks up 12 technical sell signals against only 3 bull signals. The Seattle-based multicloud application security and delivery company has attracted considerable attention from analysts as an under-the-radar AI beneficiary, with coverage noting its expansion of the VELOS product line to support AI workloads and enhance network security. That underlying narrative has helped drive valuations higher.
However, a Barchart analysis from June 2026 noted that FFIV has been underperforming the broader technology sector, raising questions about whether the AI-driven enthusiasm was fully justified by near-term fundamentals. When a stock underperforms its sector while carrying elevated expectations, technical deterioration can accelerate quickly if sentiment shifts.
For short sellers, the combination of a lofty valuation, sector underperformance and a cluster of technical sell signals makes F5 worth watching closely. That said, any renewed analyst upgrade cycle tied to AI infrastructure spending could rapidly push the stock back upward, so position sizing and stop discipline are especially important here.
3. Teradyne (TER) – 12 technical sell signals
Price: $322.30 | Daily change: -5.79%
View the full technical analysis of Teradyne
Teradyne is the largest single-day decliner in today’s list, off nearly 6%, and ties with F5 on 12 technical sell signals. The semiconductor testing company recently reached an all-time high after benefiting from strong earnings reported by one of its largest customers, and its addition to the Nasdaq 100 in a June rebalancing attracted a wave of growth-oriented investors. That rapid repricing now looks stretched on a technical basis.
Recent press linked part of Friday’s decline to TSMC’s latest results, which showed robust revenue but free cash flow compression from heavy capital expenditure — a reminder that even strong semiconductor sector data can produce mixed signals for equipment and testing suppliers. Teradyne itself reported record-breaking first-quarter 2026 results earlier in the year, validating its AI-driven strategic pivot toward more demanding chip tests.
The challenge for bears is that the fundamental story remains compelling. Teradyne is actively rebuilding its business model around AI semiconductor testing, and its index inclusion means passive buyers will be steady supporters. Short sellers entering here are effectively betting that the recent re-rating has outrun near-term earnings delivery — a plausible thesis, but one that requires careful risk management.
4. Cisco Systems (CSCO) – 11 technical sell signals
Price: $109.66 | Daily change: -1.89%
View the full technical analysis of Cisco Systems
Cisco generates 11 technical sell signals against just 2 bull signals, the lowest bull reading in today’s list. The networking giant has delivered an impressive run over the past year — one analysis cited a roughly 87% twelve-month rally — but that kind of advance naturally raises questions about whether the current share price adequately reflects future prospects. A Seeking Alpha piece from mid-July specifically flagged slower growth and market share erosion to rivals including Arista Networks, HPE and white-box competitors as meaningful downside risks.
Adding intrigue to the picture, Cisco is reportedly in discussions to acquire AI-focused cybersecurity firm SentinelOne, alongside an expanding data centre footprint in Italy and Bahrain. Large acquisitions can be binary events for share prices — they may re-rate the stock upward if investors view the deal positively, or they can weigh on the acquirer if the premium and integration risks look unattractive.
A Barchart note observed that CSCO has been trading in a relatively tight range, making it a candidate for options income strategies. For directional short sellers, a range-bound stock offers lower momentum but also signals a potential breakdown if support levels give way. The 11 sell signals suggest that technical conditions may be tilting in that direction.
5. EMCOR Group (EME) – 11 technical sell signals
Price: $750.04 | Daily change: -2.56%
View the full technical analysis of EMCOR Group
EMCOR rounds out today’s list with 11 bear signals and 3 bull signals, closing down 2.56% — a larger move than the broader S&P 500, which fell only around half a percent on the same day. The electrical and mechanical construction firm has been one of the standout performers in the infrastructure space, with Zacks upgrading it to a Strong Buy earlier in 2026 and multiple analyses highlighting its growing role in data centre cooling and complex mechanical infrastructure projects.
Elevated implied volatility in EMCOR’s options market was flagged by Zacks on 17 July, a signal that options traders are pricing in a wider range of outcomes in the near term. Surging implied volatility can sometimes precede sharp directional moves, and combined with the technical sell signals, it warrants attention from active traders.
EMCOR’s exposure to data centre construction spending is a genuine long-term growth driver, and the stock has outperformed many of its construction sector peers this year. Short sellers need to weigh that structural tailwind carefully. The technical signals suggest near-term vulnerability, but a single positive contract announcement or earnings beat could quickly reset the picture. As always, disciplined stop levels are essential.
Disclaimer: This article is produced for informational and educational purposes only and does not constitute financial advice, a recommendation to buy or sell any security, or an invitation to trade. Technical analysis identifies patterns in historical price and volume data; it does not guarantee future performance. Short selling involves the risk of unlimited losses and is not suitable for all investors. Past signals are not indicative of future results. Always consult a qualified financial adviser before making investment decisions. The Wall Street Stock Investors Club and its contributors may hold positions in securities mentioned.