If your friend exercised those options, it is possible your friend would be liable for income tax on the spread between 50k and 500k, or subject to AMT or to ot

If your friend exercised those options, it is possible your friend would be liable for income tax on the spread between 50k and 500k, or subject to AMT or to other tax consequences. This seems like quite a lot of capital to put at total risk relative to the possible gain at some uncertain point in the future. It could make sense to try to hammer out a deal with the founders. Only your friend can hazard a guess as to the ultimate likelihood of that succeeding.