Most financially savvy people would say that public company equity is almost like cash. If you are saving money for retirement, you are going to put most of your cash in the stock market, and AAPL and the stock market are highly correlated. The vesting schedule essentially forces you to save that cash for a later date (in a volatile but usually highly accretive investment vehicle). You don't have the same kinds of situations as you get with a startup where your company folds but the rest of the market is unaffected.
We are talking about stock/option grants though. You have to factor in what you think the grant will be worth over the vesting period. A lot can happen to a public stock over 4 years and your grant can easily be worth an order of magnitude less once it vests.
Cash to a lesser extent has this problem as well that you don’t know how much a dollar will be worth in four years, but it most likely less volatile than the value of equity.
I would value a 4 year 500k grant in apple stock much higher than a 4 year 500k grant in a crypto company because I believe the apple grant will better hold it’s value over the vesting period.
I would say take what most 'financially savvy' people say with a grain of salt and go ahead and do your own research or find an actual professional to sort through the details. The average lifespan of a company on the S&P 500 is dropping fairly quickly, which puts the risk of a single investment going to 0(or on a long haul downward trend) higher.
Obviously "doing your own research" is good but I think the question is totally reasonable in a tech forum where probably a very large percentage of people here have gone through this process. Also, they asked specifically about Apple. Companies that are sitting on massive amounts of cash and have trillion dollar valuations don't disappear over night, they're not gonna "drop out of the S&P" any time in the foreseeable future.
