Castle Biosciences Reports Inducement Grants Under Nasdaq Listing Rule 5635(c)(4)

Rhea-AI Summary

Castle Biosciences (Nasdaq: CSTL) announced that on Dec. 15, 2025 its Compensation Committee granted restricted stock units to 83 employees covering an aggregate of 139,494 shares as inducements for entering employment.

The grants were made under the company’s 2022 Inducement Plan in accordance with Nasdaq Listing Rule 5635(c)(4). The RSUs vest over four years: 25% on the first anniversary of each applicable vesting commencement date, then the remaining shares vest annually in three equal installments, subject to continued service through each vesting date.

Key Figures

Employees granted RSUs 83 employees Inducement RSU grants under 2022 Inducement Plan

RSU share count 139,494 shares Aggregate common stock underlying inducement RSUs

Initial vesting tranche 25% Vests on first anniversary of vesting commencement date

Vesting period 4 years RSUs vest over four years subject to continued service

Follow-on vesting installments 3 equal installments Annually after first anniversary, subject to service

Prior close price $39.6 Price before inducement RSU news

52-week high $40.6099 Pre-news 52-week high comparison

52-week low $14.59 Pre-news 52-week low comparison

Market Reality Check

$39.44 Last Close

Volume Volume 277,813 vs 20-day average 454,798, at 0.61x typical trading activity before this news. low

Technical Shares traded above the 200-day moving average of 22.77 with a prior close of 39.6 before this news.

Peers on Argus

Before this RSU inducement news, CSTL was down 0.15% while peers were mixed: FLGT up 1.23%, CDNA down 2.79%, MYGN down 4.69%, PSNL down 1.31%, NEO down 0.6%, indicating stock-specific factors rather than a broad sector move.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 17	Clinical study data	Positive	+1.6%	Large UM study showed DecisionDx-UM + PRAME improved survival prediction.
Dec 12	Clinical validation data	Positive	+1.7%	Meta-analysis confirmed TissueCypher outperformed traditional risk stratification.
Dec 09	Clinical endorsement	Positive	+0.4%	Expert panel endorsed DecisionDx-Melanoma as best-practice prognostic tool.
Nov 17	Workplace recognition	Positive	+1.5%	Fifth consecutive Houston Chronicle Top Workplace and multiple culture awards.
Nov 14	Clinical performance data	Positive	-2.0%	New data showed DecisionDx-Melanoma improved SLNB decisions and prognosis.

Pattern Detected

Recent news has focused on positive clinical data and workplace recognition, typically followed by modestly positive price reactions, with one notable negative divergence.

Recent Company History

Over the past two months, Castle Biosciences has reported multiple positive developments, including new data on DecisionDx-UM and DecisionDx-Melanoma, a systematic review supporting TissueCypher, and a fifth consecutive Houston Chronicle Top Workplaces award, totaling 13 workplace awards in 2025. Most of these news items saw positive 24-hour price reactions, suggesting markets often reward Castle’s clinical validation and culture-related announcements. Today’s RSU inducement grants add to this backdrop as an employment-related corporate update rather than a clinical or financial catalyst.

Market Pulse Summary

This announcement details inducement restricted stock unit grants covering 139,494 shares for 83 employees under Nasdaq Listing Rule 5635(c)(4), vesting over 4 years with an initial 25% tranche. It follows a series of positive clinical and workplace updates that previously saw mostly favorable price reactions. Investors may track how ongoing equity-based compensation, insider transaction trends, and future clinical data interact with the stock’s position near its recent 52-week high.

Key Terms

restricted stock units financial

"granted restricted stock units (RSUs) to 83 employees covering an aggregate"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

rsus financial

"granted restricted stock units (RSUs) to 83 employees covering an aggregate"

RSUs, or restricted stock units, are a form of company shares given to employees as part of their compensation. They are typically awarded with certain restrictions, such as a waiting period before they can be fully owned or sold, similar to earning a gift that becomes fully yours over time. For investors, RSUs can impact a company's stock offerings and reflect how much the company relies on stock-based incentives to attract and retain talent.

nasdaq listing rule 5635(c)(4) regulatory

"pursuant to the Company’s 2022 Inducement Plan in accordance with Nasdaq Listing Rule 5635(c)(4)."

NASDAQ Listing Rule 5635(c)(4) is a rule that requires a company to get approval from its shareholders before selling a large amount of its shares, usually over 20%. This helps protect investors by making sure the company doesn't flood the market with new shares without their say, which could lower the stock's value.

AI-generated analysis. Not financial advice.

FRIENDSWOOD, Texas, Dec. 19, 2025 (GLOBE NEWSWIRE) -- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced that on Dec. 15, 2025, the Compensation Committee of its Board of Directors granted restricted stock units (RSUs) to 83 employees covering an aggregate of 139,494 shares of common stock as an inducement material to their entering into employment with Castle Biosciences. The RSUs were granted pursuant to the Company’s 2022 Inducement Plan in accordance with Nasdaq Listing Rule 5635(c)(4).

The RSUs will vest over four years, with 25% of the shares vesting on the first anniversary of the applicable vesting commencement date, and the balance vesting annually thereafter in three equal installments, subject to the employee’s continued service through each applicable vesting date.

About Castle Biosciences
Castle Biosciences (Nasdaq: CSTL) is a leading diagnostics company improving health through innovative tests that guide patient care. With a primary focus in dermatologic and gastroenterological disease, we develop personalized, clinically actionable solutions that help improve disease management and patient outcomes.

We put people first—empowering patients and clinicians and informing care decisions through rigorous science and advanced molecular tests that support more confident treatment planning. To learn more, visit www.CastleBiosciences.com and connect with us on LinkedIn, Instagram, Facebook and X. 

DecisionDx-Melanoma, DecisionDx-CMSeq, i31-SLNB, i31-ROR, DecisionDx-SCC, MyPath Melanoma, AdvanceAD-Tx, TissueCypher, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are trademarks of Castle Biosciences, Inc.

Investor Contact:
Camilla Zuckero
czuckero@castlebiosciences.com

Media Contact:
Allison Marshall
amarshall@castlebiosciences.com

Source: Castle Biosciences Inc.

FAQ

What did Castle Biosciences (CSTL) announce on Dec. 19, 2025 about employee equity?

The company announced RSU inducement grants made Dec. 15, 2025 to 83 employees covering 139,494 shares under the 2022 Inducement Plan.

How do the Castle Biosciences (CSTL) RSUs vest and over what period?

The RSUs vest over four years: 25% on the first anniversary of the vesting commencement date, then annually in three equal installments, subject to continued service.

Under which Nasdaq rule were Castle Biosciences (CSTL) inducement grants approved?

The grants were made in accordance with Nasdaq Listing Rule 5635(c)(4) under the company’s 2022 Inducement Plan.

How many employees received RSU inducement grants from Castle Biosciences (CSTL)?

A total of 83 employees received restricted stock unit inducement grants.

How many total shares were covered by Castle Biosciences (CSTL) RSU inducement grants?

The inducement grants covered an aggregate of 139,494 shares of common stock.