Some of them sold much more volatility, via variance swaps, with quite disastrous results.
https://www.institutionalinvestor.com/article/b1lffwvwdh7xtq...
Selling puts, though, is a fools game unless the market has already really tanked. Black Scholes isn't perfect, yadda, yadda.
I guess one issue with this approach is that it somewhat assumes a period of low-inflation between now and option expiry (unless you're factoring that into the 15% expected return).
Buy at $400 (price at time of writing) sell an option at $460 for January which comes with a $42 premium[0] at time of writing, so if the stock goes up 15% over the six month period the total return is $102 per share, or about 25% return. If inflation is, say, 4% per annum due to Covid pushing it a bit higher than normal, then the total return is ~23% vs what would have been ~13% for doing the same play without selling the option, so the real return is around 75% higher than the alternative where the option was not sold.
Usually it's around 30% more, so right now is an especially good time for this play if you think that Apple will at least hold its value.
[0] https://finance.yahoo.com/quote/AAPL220121C00460000?p=AAPL22...
For example, if the theory goes that more people will want to buy apple now that the price is a "steal" (people think it's harder to 2x a big number than a small number) then it could go above that on open.
I prefer to believe that stocks are not in a bubble of such epic proportions that a stupid split can be an "event".
That is the split of Google A and C some years back, where Google added a new class of shares with different voting power.
In the Apple split each share after the split will be worth 1/4th, have 1/4th voting power, will receive 1/4th of dividend, etc. just reading happens in smaller fractions.