The automatic 2.5 percent trading system is about an automatical exit when the stock hits either a 2.5% gain or a 2.5% loss. The entry signal can be a breakout of a trading range, a swing back after a downturn, a news event, a crossing of moving averages, the break of a line of resistance or support or whatever cyclical signal you may imagine. But it can be a counter cyclical entry signal too, like a line of support or resistance which seems to hold.

After entering the market in what seems to be an asymmetrical chance which skews the ubiquitous symmetry of chances of 50:50 in your favor, you simply would enter 2 sell orders 2.5% above and below the entry price. The exact percentage can be adjusted to the particular stock or market. Interestingly the offset hasn't necessarily to be the same in both directions. E.g. 4% above and 5% below may work too. This way the higher sell point can be adjusted to match a line of resistance and the lower sell point can equal a new signal for breaking the next line of support, which otherwise would be a sell signal triggering a short trade itself.