HALO, which stands for heavy assets, low obsolescence, is the trade of the year. Global investors have been bidding up makers of everything, from cars to PCs, betting that many may benefit from the trillion-dollar artificial intelligence boom.But worries are heightening that this trade is more a fad than a trend. A parabolic rally in the Philadelphia Semiconductor Index has drawn comparisons to 1999, before the dot-com bubble burst. Further, there’s evidence that the biggest winners from this AI stock boom are aided by momentum chasers. The pick-and-shovel theme might just be a nice story that investors tell themselves to justify risk-taking.Bloomberg OpinionSubscribe to gift this articleGift 5 articles to anyone you choose each month when you subscribe.Subscribe nowAlready a subscriber? Fetching latest articles