If you're an accredited investor (make sure you meet the financial criteria) you can cold email seed/pre-seed stage companies. These companies typically raise o

If you're an accredited investor (make sure you meet the financial criteria) you can cold email seed/pre-seed stage companies. These companies typically raise on SAFEs and may have low minimum investments (say $5k or $10k). YC lists all their companies here: https://www.ycombinator.com/companies https://www.ycombinator.com/companies. Many companies are likely happy to take your small check if you are a nice person and can be even minimally helpful to them. Note that for YC companies you'll probably have to swallow the pill of a $20M valuation or so.