The idea of copyright did not exist in ancient times, when authors frequently copied other authors at length in works of non-fiction. This practice was useful, and is the only way many authors' works have survived even in part. ↗
In silent movies, they tended to put the camera down, and everybody walked in front of it and acted, and then they all walked off. Cutting was quite infrequent. ↗
Having the opportunity to follow the market frequently gives you the opportunity to see if you need to reevaluate your portfolio. But reevaluating your portfolio shouldn't trigger a sell signal so frequently. ↗