BTAL combines a strategy of going long on low-beta stocks and shorting high-beta stocks. It is a market-neutral strategy that helps to balance a portfolio. A 5% position of your overall holdings in a market-neutral is a good rule of thumb.
It is a very simple and easy way to give your portfolio downside protection without having to worry about selling calls or buying puts. It is something that should always be a part of your portfolio, so don't shy away when you see red! Beef up the position or top it off when it's down. It will hit $27.85 again when the market has its next drop. It is actively managed and a 5 star Morningstar fund the last I checked.
Basically, when the market goes down, this goes up. It acts as a buffer for your portfolio.