Why is Twist Bioscience stock sliding today?

Twist Bioscience Corp stock fell 7.1% in pre-open trading after the company reported its fiscal fourth-quarter 2026 results before the opening bell, delivering a per-share loss that was meaningfully wider than Wall Street had anticipated. Analysts had been expecting a loss of roughly $0.38 per share on revenue of approximately $123.6 million, representing about 25% year-over-year growth, but the actual EPS came in roughly 16.7% worse than consensus, even as revenue modestly topped estimates.

The earnings miss carried extra weight given the elevated expectations baked into the stock’s valuation. Heading into today’s report, the company’s price-to-sales ratio stood well above both its own historical median and typical industry multiples, meaning any shortfall on profitability metrics was likely to be punished. Compounding the pressure, a bearish report published the prior week by The Bear Cave — owned by Hunterbrook Media — had already argued that Twist trades at a premium no peer commands, and that its recent rally may have run ahead of underlying fundamentals. Short interest of around 16% and $146.7 million in insider selling over the past twelve months had also kept sentiment fragile.

The broader market offered little cushion, with the NASDAQ declining 0.9% and the S&P 500 slipping 0.4% in today’s session, a headwind that disproportionately affects high-beta growth names like Twist, which carries a beta of approximately 2.25. The life-science tools and genomics sector has broadly faced scrutiny over whether AI-driven demand narratives can translate into near-term earnings power, with peers such as Illumina also experiencing pressure in recent weeks.

Together, a profitability miss against a premium-valued stock, residual damage from the prior week’s short-seller report, elevated short interest, and a risk-off macro backdrop combined to push Twist Bioscience shares sharply lower in pre-market trading, erasing a significant portion of the gains the stock had built over recent months.