The SAFE - Sample Agreement for Future Equity - has become a popular money raising tool for entrepreneurs since being introduced by Y-Combinator in 2013. They're fashioned after but completely distinguishable from traditional convertible notes (where the investor is entitled to shares of company stock if the venture doesn't repay the loan by a deadline). A SAFE can be an effective fundraising tool. Entrepreneurs should know what they are, how they work, and their limitations.