Notice that since the upward trend was pretty steady, the potential return seems not so much greater than Buy and Hold. Except B/H would have been 100% invested the whole time and remained vulnerable even now, while X_Dev has completely cashed out and locked in the gains.
After hanging on for a whole year, through severe slides and spikes, B/H would have barely changed at all, while X_Dev'ing would have more than doubled the portfolio.