As others mentioned, unexplainable business models or money coming out of nowhere are major red flags. A few others to look out for if you are applying for a job:
1. Few or no internal controls. A medium-size or larger company not having a CFO is particularly questionable.
2. People in high positions, including the CEO, lack qualifications or experience. Often the CEO will hire inexperienced or incompetent people for high-level positions because they a) won't figure out what is going on or b) can figure it out, but are too grateful for the position to say anything. Or maybe the CEO never finished college in a field where everyone has a PhD (think Elizabeth Holmes).
3. History of experienced / qualified people joining the company and leaving soon after
4. Seemingly unexplained success.
5. Extravagant spending and inappropriate workplace behavior.
6. Cult of loyalty to the CEO and/or a "circle" around this person, including close interpersonal relationships.
The pipeline into our collective understanding of tech is now:
scifi hype pitch -> VC flood of investment -> press releases across world -> governments worry -> disappointing IPO -> malpractice -> one or more execs arrested/sacked -> media elite across world convinced new invention will destroy the world
uber creates a taxi service, amazon an online mall, openai a ghost writer -- and we're all subject to an industry of VC hype men desperately trying to get those multiples above 20x by assaulting the popular consciousness with delusional BS
Really shows how he did it using the steps detailed above.
https://www.netflix.com/title/81466159?preventIntent=true
The Wolf of wall street film also shows the same pattern.
I just had a meeting for a Job. Flags 2 and 4 were there already. Unclear business model. I have a PhD. While this does not make me necessarily smart, I have an insight and understanding of many industries. If I don't understand you business in a few sentences, you are either a fraud or are much much smarter than me.
I give you a few more red flags, but remember, this are red flags, not proof of fraud.
1. Operating over many jurisdictions.
2. Opaque payments/salaries. Either to good to be true or commission based.
3. People who don't understand numbers and often are off by a magnitude. The stock is worth 5 bucks, could go up 200 times and then ist 10k per stock. Company is worth now X billion, could be 200 times more. 200 times? We are taking market capitalization of the biggest players here, is this even possible for this specific industry?
4. Mentioning big names. Studied at MIT etc. (but very likely did not) Or for low lever frauds, build trust by assigning with law enforcement. (My farther works for the police, is a judge etc.)
5. If you know an industry you know the stuff, you know the numbers and you are never caught off guard by a question.
But really, anything to do with crypto or NFTs should be a red flag at this point.
If your gut says they might be criminals, they are probably criminals.