Before investing in a startup, there are several factors to consider:- Understand the startup's business model and revenue streams- Evaluate market demand and team experience- Examine the startup's financial health and funding sources- Consider the competitive landscape and potential exit strategiesDifferent criteria apply for evaluating startups at different stages:- Pre-seed stage: Consider founder's background, previous ventures, market size, and skills- Growth stage: Evaluate market strategy, channels, and execution team- Unicorn stage: Limited potential for individual investors due to valuation and growth