Some time ago I submitted a rather silly strategy. It used the lunar phase to buy, well, mostly anything really. It was the simplest of strategies: on the close of the first (or second) day of the 7th 8th phase of the Moon -- GO LONG. Get out on the start of the 8th phase.
Seriously.
I added a simple filter using the MFI (money flow index) which helped to exclude some obvious ugly patches but for the most part this phenomena has been in place for the last 6 years. And remains so. This strategy works even better if you use hourly data (not tested here) and you wait until you've got a higher high within about 4 or 5 periods.
To date I have not figured out why this strategy works. Nor has anyone offered a logical rational. But it works. Here for your incredulous wonderment I present a 2.9 leveraged version.
If you figure out how to take those couple of nasty dips out of it... do share.