Take 2008. Your real estate is depreciating. Your national currency is losing value. All the all while crude oil is steadily growing in price. This last fact most probably escapes your attention, as you are divorced, jobless and squatting in suburban Detroit.
If, however, you are an online trader, you simply recognise these three trends and act upon them: short your currency (that is called hedging, by the way), hold to your real estate and go long the oil price.