I think if you're talking on portfolio level a lot of these things are used as signals and parts of a greater whole. In that sense, they can indeed add value.

I think if you're talking on portfolio level a lot of these things are used as signals and parts of a greater whole. In that sense, they can indeed add value. My current project is a modern version of a classic Harry Browne portfolio with even asset allocations to gold/bonds/equity/commodities, with optional layers of sophistication according to spec needs. Something like systematic macro could be analyzed as a standalone return stream, but it's more useful when considered as an input into allocation/leverage adjustments (ex: if geopolitical uncertainty readings are high, cut down the trend following exposure). Even the more robot/quant stuff like vol trading feeds back into the wider portfolio management and portfolio construction level to some degree.