1. Momentum. If they say they've been working on it for six months, do they have a lot to show for it (ideally that derisks the company)? If not, you might be d

1. Momentum. If they say they've been working on it for six months, do they have a lot to show for it (ideally that derisks the company)? If not, you might be disappointed by their future progress as well. At the least, you might be doing the heavy lifting and should receive substantial equity. 2. Honesty/Transparency. If you are joining early on as a vital co-founder (e.g. mostly equity compensation), I would expect equal access to the cap table, founding documents, have a co-founder agreement, etc. If your future co-founders repeatedly hide/omit important details or tell you fishy things (e.g. % ownership doesn't matter, or they don't send a written cap table after verbally agreeing to an equity split), I would run. In any event, I highly recommend having a lawyer look over your agreements! 3. Market Understanding. Are your co-founders expert in this field? If not, have they done substantially more than "have an idea" to test the market? I would also ensure alignment on things like passion for the field and exit plans.