With tech companies continuing to boost AI spending, the valuation of many chipmakers are increasingly expensive. Chip stocks have become a favorite way to bet on artificial intelligence. But after big runups in companies like Broadcom Inc., investors are turning to an often overlooked group — suppliers of the gear used to make semiconductors. Most Read from Bloomberg Teradyne Inc., a provider of tools used for testing chips during the manufacturing process, has nearly doubled from an April low and is up ...