Worst S&P 500 stocks in the first half of 2026.

Three dominant themes.

Software: 18 of the bottom 40. Nearly half.
🧾 Intuit $INTU -60%
🏠 CoStar $CSGP -58%
💼 Accenture $ACN -53%
💻 Cognizant $CTSH -53%
📺 The Trade Desk $TTD -52%
📊 Gartner $IT -49%
👔 Workday $WDAY -43%
☁️ Salesforce $CRM -41%
🎨 Adobe $ADBE -41%

Tax prep ($INTU), professional tools ($ADBE), CRM ($CRM), HR ($WDAY), ad-tech ($TTD), IT consulting ($ACN, $CTSH). AI agents are threatening the same workflows these companies monetize. The market is repricing the entire software layer.

MedTech & Healthcare: 6 stocks, led by $BSX -55%.
🫀 Boston Scientific $BSX -55%
💉 Insulet $PODD -46%
🐾 Zoetis $ZTS -42%
🏥 Universal Health $UHS -32%
🤖 Intuitive Surgical $ISRG -30%
🩺 Abbott $ABT -27%

Insulet ($PODD, insulin pumps) is the clearest GLP-1 casualty: fewer diabetics means fewer pump users. Boston Scientific dropped 55% despite strong fundamentals, a pure valuation reset after trading at 50x+ earnings. Zoetis ($ZTS, animal health) caught a downgrade cycle.

Consumer: tariffs and slowing spend.
🧘 Lululemon $LULU -45%
🚜 Tractor Supply $TSCO -36%
👟 Nike $NKE -35%
🍕 Domino's $DPZ -28%

Nike and Lululemon share the same problem: global supply chains exposed to tariffs, plus slowing consumer spend in core markets. Tractor Supply ($TSCO) is a rural consumer bellwether signaling real weakness. Even Domino's ($DPZ), typically defensive, is down 28%.