But I do hear from time to time that trend-following cannot work now. That it was a temporary successful formula that could only work in the 80's or 90's or whenever. That there are now so many people doing it that it has been arbitraged out of the markets.
Okay, can you explain? How can a trend be arbitraged out? A trend is a price movement in one direction (with noise, of course). If it's moving up or down consistently throughout a period of time (perhaps above a certain % threshold of movement), which obviously happens all the time, how can anyone claim that it's arbitraged out? I mean, it happened right? If you BLSH, then profit.