The index’s advance is driven by an almost 35% rise this year for the The companies in that ETF have benefited from undying chip demand from the big internet and software companies that are building data centers. Also, the is up more than 10%, driven by several manufacturers that supply products for data centers. The reason: the data center-exposed stocks are vulnerable to steep declines if one of the large internet or software companies signals it will slow down the growth of its investments in data centers.