I'll never have $50m, but with the $1m I do have, I'm investing in the following SectorSurfer portfolio: (imgur is blocked on my network)
http://pasteboard.co/Sx5okLl.png
Yes, these are back-tested results. Yes (of course) there's not chance this will continue to have an annualized 50%+ return. Nothing will. But, at least in my book, when you find an investment strategy that has consistently spanked the S&P for 28 years in a row, then I conclude that the chances are good that it will continue to outperform the market by some percentage. If you can manage to beat the market even by a couple percentage per year, you're well ahead of the game.
The creator of SectorSurfer is a Standford engineer (who happens to be a neighbor of mine), and has spent the last 10 years perfecting the software, and the service launched commercially in 2009. Clearly this kind of thing is not everyone's cup of tea. If you want to the conventional wisdom to buy and hold the S&P, that's perfectly fine. I basically did this myself for most of the last 20 years.
In case you're wondering about the credibility of this service, SectorSufer won a 2016 NAAIM Wagner award for the following paper:
http://sumgrowth.com/downloads/Automated%20Polymorphic%20Momentum.pdf
If anyone is curious about the service, send me a note! I've been investing for 25 years, and I seriously think it's one of the best kept investment secrets out there. Gook luck!