Castle Biosciences (NASDAQ:CSTL) Shares Gap Down – Here’s Why

Shares of Castle Biosciences, Inc. (NASDAQ:CSTL) gapped down before the market opened on Friday . The stock had previously closed at $31.88, but opened at $29.87. Castle Biosciences shares last traded at $30.2290, with a volume of 212,078 shares.

Key Stories Impacting Castle Biosciences

Here are the key news stories impacting Castle Biosciences this week:

• Positive Sentiment: Q4 / FY2025 results and 2026 revenue guide: Castle reported FY2025 revenue of $344M (above guidance) with Q4 revenues roughly in line with estimates and beat on EPS (Q4 GAAP EPS -$0.08 vs. consensus -$0.23). Management set 2026 revenue guidance of $340–$350M (slightly above the prior consensus ~$335M), supporting near‑term top‑line growth expectations. Castle Biosciences outlines 2026 revenue target
• Positive Sentiment: Product momentum and new launch: Core test reports (DecisionDx‑Melanoma and TissueCypher) rose ~37% in 2025 (TissueCypher +86%), and Castle launched AdvanceAD‑Tx (limited access), which expands the addressable market in atopic dermatitis. These operational wins support longer‑term growth potential. Earnings press release
• Positive Sentiment: Analyst upgrade / price target lift: Robert W. Baird raised its price target to $44 and reiterated an Outperform rating, signaling bullish analyst sentiment and implying notable upside from current levels. Baird raises target
• Neutral Sentiment: Additional coverage & materials: Earnings and investor materials (call transcript, slide deck) are available for deeper due diligence — useful for active investors reviewing guidance detail and management commentary. Press release & slide deck
• Neutral Sentiment: Street view: Recent coverage shows a generally constructive analyst stance (average “Moderate Buy” / multiple buy/outperform ratings), which can support sentiment if fundamentals hold. Analyst ratings roundup
• Negative Sentiment: Profitability and accounting headwinds: Despite revenue growth, Castle reported a GAAP net loss for 2025 of $24.2M (vs. net income in 2024) and adjusted EBITDA declined materially (from $75M to $44M). A one‑time acceleration of amortization (IDgenetix) and other items reduced margins — a drag on near‑term earnings power. Zacks earnings summary
• Negative Sentiment: Insider selling and discontinued tests: Public filings and summaries show heavy insider sales in recent months and the discontinuation of IDgenetix (lost volume), both of which can pressure sentiment and raise governance/operational questions for investors. Quiver / results summary

Analyst Ratings Changes

A number of equities research analysts have recently commented on CSTL shares. BTIG Research raised their price target on Castle Biosciences from $38.00 to $50.00 and gave the stock a “buy” rating in a research report on Friday, December 12th. Weiss Ratings restated a “sell (d)” rating on shares of Castle Biosciences in a report on Monday, December 29th. Canaccord Genuity Group upped their price target on shares of Castle Biosciences from $37.00 to $50.00 and gave the company a “buy” rating in a report on Monday, December 22nd. Robert W. Baird upped their price target on shares of Castle Biosciences from $41.00 to $44.00 and gave the company an “outperform” rating in a report on Friday. Finally, Guggenheim raised their price objective on shares of Castle Biosciences from $43.00 to $47.00 and gave the stock a “buy” rating in a report on Monday, January 26th. One equities research analyst has rated the stock with a Strong Buy rating, seven have assigned a Buy rating and one has issued a Sell rating to the stock. According to MarketBeat.com, the stock presently has a consensus rating of “Moderate Buy” and a consensus target price of $47.57.

Castle Biosciences Stock Down 7.2%

The company has a current ratio of 6.47, a quick ratio of 6.31 and a debt-to-equity ratio of 0.02. The company has a market capitalization of $863.15 million, a P/E ratio of -34.79 and a beta of 1.06. The firm’s 50 day moving average price is $37.17 and its two-hundred day moving average price is $31.21.

Castle Biosciences (NASDAQ:CSTL) last announced its earnings results on Thursday, February 26th. The company reported ($0.08) EPS for the quarter, topping the consensus estimate of ($0.23) by $0.15. Castle Biosciences had a negative net margin of 7.02% and a negative return on equity of 0.89%. The business had revenue of $81.88 million during the quarter, compared to analysts’ expectations of $81.19 million. Equities research analysts forecast that Castle Biosciences, Inc. will post 0.44 EPS for the current year.

Insider Activity

In other Castle Biosciences news, COO Kristen M. Oelschlager sold 14,888 shares of the firm’s stock in a transaction that occurred on Wednesday, December 17th. The stock was sold at an average price of $39.31, for a total value of $585,247.28. Following the completion of the transaction, the chief operating officer directly owned 12,323 shares in the company, valued at $484,417.13. This trade represents a 54.71% decrease in their ownership of the stock. The transaction was disclosed in a document filed with the Securities & Exchange Commission, which is available through this link. Also, insider Derek J. Maetzold sold 4,017 shares of the business’s stock in a transaction that occurred on Tuesday, January 20th. The stock was sold at an average price of $40.01, for a total value of $160,720.17. Following the transaction, the insider directly owned 87,715 shares in the company, valued at $3,509,477.15. This trade represents a 4.38% decrease in their position. Additional details regarding this sale are available in the official SEC disclosure. Insiders sold a total of 29,617 shares of company stock valued at $1,167,887 in the last 90 days. 6.50% of the stock is owned by corporate insiders.

Hedge Funds Weigh In On Castle Biosciences

Several hedge funds and other institutional investors have recently made changes to their positions in CSTL. Federated Hermes Inc. acquired a new position in Castle Biosciences during the fourth quarter worth $26,000. Kemnay Advisory Services Inc. bought a new position in shares of Castle Biosciences in the 4th quarter valued at about $35,000. Farther Finance Advisors LLC increased its stake in shares of Castle Biosciences by 139,100.0% during the 3rd quarter. Farther Finance Advisors LLC now owns 1,392 shares of the company’s stock worth $32,000 after purchasing an additional 1,391 shares during the last quarter. Mirae Asset Global Investments Co. Ltd. raised its holdings in shares of Castle Biosciences by 26.5% in the 4th quarter. Mirae Asset Global Investments Co. Ltd. now owns 1,418 shares of the company’s stock valued at $55,000 after purchasing an additional 297 shares during the period. Finally, State of Alaska Department of Revenue acquired a new stake in Castle Biosciences in the 3rd quarter valued at about $35,000. 92.60% of the stock is owned by institutional investors.

About Castle Biosciences

Castle Biosciences, Inc is a molecular diagnostics company specializing in the development and commercialization of prognostic and diagnostic tests for patients with dermatologic conditions. The company’s proprietary portfolio of genomic assays is designed to improve risk assessment and guide clinical decision-making for individuals with skin cancers and other skin-related diseases. By combining genomic data with advanced statistical algorithms, Castle Biosciences seeks to provide actionable insights that help physicians tailor treatment plans and monitoring strategies.

The company’s flagship test, DecisionDx-Melanoma, evaluates the probability of metastasis in patients diagnosed with cutaneous melanoma, supporting more personalized surveillance and therapeutic approaches.