It's an interesting concept that you bring up, and is actually one of my favorite trading strategies. I wouldn't necessarily do 7 years, but I definitely do a similar strategy. Personally, mine deals with bonds and stocks. I try to enter the market when its low, ride it up to around the amount where it started going down + whatever the deviation was between that and it's lowest point. At that point, or gradually as it gets to that point, I would take out 50-75% of my position and either hold onto it, or put it into bonds. If stocks decline, bond prices go up, and rinse and repeat. If stocks continue going up, well then you just realized your profit.

Currently I'm not invested in the traditional stock markets at all as I'm expecting a correction or possible recession in the near future. I will however be getting into the market once that happens.