Companies Act (Cap. 50): Primary legislation governing corporate matters including share issuance and transfer requirements, directors' duties and obligations, share capital structure regulations, and corporate governance requirements.

Securities and Futures Act (Cap. 289): Regulates securities offerings, disclosure requirements, restrictions on share transfers, and provides exemptions for private companies.

Income Tax Act: Governs tax implications of share transfers, tax treatment of share-based compensation, and stamp duty considerations.

Employment Act: Relevant when founder is also an employee, covering employment-related obligations and vesting conditions if applicable.

Contract Law (Common Law): Foundational principles governing contract formation, consideration requirements, terms and conditions, breach and remedies.

Singapore Exchange (SGX) Rules: Relevant if future listing is contemplated, including compliance requirements for public listings.

MAS Guidelines: Regulatory guidelines from the Monetary Authority of Singapore affecting corporate governance and securities matters.

Company Constitution: Company's governing document that sets out the rules for company administration and shareholder rights.

Shareholders' Agreement: Existing agreements between shareholders that may affect or need to be considered in the stock purchase agreement.